I do something similar for daily notes for work. I have a shell alias `tdw` for `TODO work` which opens a YYYY-MM.md file in vim. Inside of that markdown file I use a vim macro that generates a date similar to what is shown in calendar.txt, where I take notes about what I am working on and what I have worked on. Here's ane example of what it looks like:
## 2025-02-27 W09 Thursday
- Team standup
- Looking up flights to Venus
- Meeting with Acme
- Discuss hydrocoptic marzlevanes
- TODO: read up on them <http://example.com/docs/hydrocoptic-marzlevanes>
- (personal) Feed the dragon
- #5934 Fix glitch in dingle arm reciprocator
I kind of like the calendar.txt idea of prefixing every line with the date, because it makes grepping easier, but at the same time, it doesn't allow for sub-lists and more detailed notes about what was worked on. It hasn't been a big enough problem to deal with though, because of things like `grep -i -B10 encabulator`
The vim macro I use is:
" Macro To Do Today
nmap mtdt <esc>O<CR><esc>k"=strftime('## %F W%V %A')<CR>Pa<CR><CR>-
As a file format, this is just fine, but I feel like there's some conflation between a file format and software meant to interact with that format.
I use plain text accounting for my business, and it's lovely to be able to enter bookkeeping data with a plain text editor and keep it all under version control, but the next step is using a program such as hledger or beancount to work with that data.
I'd love to work with plain text calendar software, but it would still need to do things such as provide a mechanism to work on my desktop and mobile device. It would need to handle recurring events automatically, and it would need to allow me to invite others to events and ideally to track when they've accepted or rejected my invites.
I'd need to be able to update, cancel or propose to move events in such a way that others would be updated.
I wish I knew of a good command line tool to interact with CalDav or similar servers, or that I could maintain my calendar in a file format and then handle the synchronization automatically.
Maybe calendar.txt could play a role in that, but on its own, it's not quite enough for me.
For reminders and other automated actions,
pydry suggested "orgzly revived with org mode"; and kruffalon suggested 'remind'. I have not tried those, but they might be better options for notifications and reminding than calendar.txt.
I use calendar.txt on a cell phone with Markor text editor. For my desktop, I just use micro editor on terminal, the same I use for most text editing tasks.
Bookkeeping using plain text files sounds both interesting and challenging.
> Bookkeeping using plain text files sounds both interesting and challenging.
It has quite a bit of a following; I personally would never switch back to some more "complete" application. I believe all the most popular implementations are listed here: https://plaintextaccounting.org/
Nice idea, but the calendar format is a bit verbose for my taste. Week number is something I would have to look up constantly and surely get wrong more than once.
If you want to follow UNIX philosophy, why don't you write an augmenter/converter tool `caug` that adds "computed" information such as week number, weekday or even relative date?
That was my first thought too; I often use Google Sheets/Excel as a lightweight todo calendar, and I'll make formulas to calculate week-of-year and day-of-week. These lists are so lightweight and adhoc that having to do that kind of calculation would be enough friction to not maintain the lists after a short period
With some traditional GUI calendar software, I was often hunting and miscopying week numbers. Some software also had a weird (non ISO-8601) idea of week numbers.
In case you need calendar.txt after 2033, I wrote a small tool [2] to generate more templates.
It's conflating a format for recording calendars with a syntax the user needs to write.
That syntax looks quite brittle and not very intuitive. One day = one line would get unwieldy fast. It doesn't localise well and there's no obvious way to implement recurring events beyond daily actions. (From what I can see at least?)
You could build a client on top of that but then, you lose the benefit.
It's a neat idea and it's good to see someone share a simple concept that works for them. But I don't see it working for most people.
> Unix philosophy. It's one day, one line. You can grep (only show lines).
Surprisingly, grep is able to output several lines, so even if you were to use a (say) more sensible format of one line per event, grep could still output all lines, and display them.
I like this, but need more detail in my log and have too many things in a given day to have them all on a line. Had the following idea, and will try it out at some point. Call it calendar.md
Use calendar.txt format and method with the following changes:
1) Use markdown, with a top level heading of Calendar (so inclusion is easier) and the portion
2) Use :tag: instead of +tag. Tags can be run together (:tag:tag2:). This helps with Org mode compatibility
3) Third level heading for each event in day, following same format as calendar.txt
4) text under heading is for notes about the event
5) Searching and seeing info on event in day, or summary about day is no longer easy with grep. This is the biggest drawback from not using calendar.txt. Overcome by writing a tool mgrep that is specifically designed to search markdown files in a Markdown aware way (search headings or specific level of headings, show all headings under matching heading or just one level under, show all content under matching headings, search text and show either lines or section text is in optionally along with ancestry of headings).
6) Create CalendarMDMode, minor mode designed to facilitate calendar.md use and editing within Emacs, requires OrgMode, things like shortcuts for new date, new event, in-editor use of mgrep, etc.
I’m skeptical about convenient plain text is, compared to more structured formats, once we try to encode even more of the conveniences we get out of current calendaring (e.g. time zone shifting, notes of indefinite length, events that last the whole day, repeated events…)
There are a few more structured formats for calendaring that share the virtues of their workflows: if we used JSON, would jq be a UNIXy tool? What about sqllite and commandline queries? Both would be much more easier for my overloaded mind - especially when parsing records - without adding more inherent complexity beyond a sufficiently overloaded raw text calendar.
I created a super-simple CalDav-esque web endpoint in my personal website that receives HTTP requests from a command line tool, stores the calendar events, and then returns them as a dynamic ICS file. Then, I use Apple’s Calendar app to subscribe to a “hidden” URL and iCloud automatically distributes the subscription to all my devices.
It sounds super dumb but it works so well.
The main feature is that I can categorize the events (personal, family, work, friends, etc.) and share individual URL’s with other people. Admitedly, I didn’t try solving this problem with Google Calendar, Apple Calendar, or any other calendar service, mostly because I wanted to own my data and also learn a bit more about CalDav itself.
This is close to what I want. I manage all my calendars in radical caldav server and want a sharable calendar that just shows the empty spots between all calendars with minimal detail fo easy scheduling.
* [ ] YYYY-MM-DD
* [ ] 1800: Dinner with parents
* [x] Walk the dog
* [ ] YYYY-MM-DD
* [ ] 0900: Interview new recruit
* [ ] Prepare interview questions
* [ ] Upload result to HR system
This worked really well for me and was easily searchable. One benefit would be that it is easily trackable in Git.
These days I have a little A6 lined notebook and manually list tasks there. Each page is a new day and the tasks are listed similarly. The only modification is that sometimes I put some letters to theme a task, i.e.:
I use a small paper planner that I keep in my pocket at (nearly) all times. People are taken aback and ask why I don't use something more modern, but why should I? This works better, for me, than anything else I ever tried.
It's unfair to computers how well paper planners worked. Among with todo.txt, paper calendars were an inspiration and a benchmark for writing calendar.txt.
This is a much nicer format than the one in the linked article.
I think my approach would be to generate a file in Markdown, then import that into a good Markdown editor. You could generate it each week or month from a template, making it easier to add repeating tasks like exercise and dog walking.
I think the format I suggested would parse in markdown, but I created it pre-markdown.
For me the best parts are:
1. You could write a parser very quickly.
2. It's very easy to edit and add to as a human.
3. It can easily be tracked in git or via a diff-based tool.
I did already think about the repetitive tasks, a long time ago I used to have a tool that would look at the past tasks and recommend future tasks (with appropriate distributions). One example was booking a dentist appointment every 6 months, even if I forgot to schedule something it would remind me to book one in, dismiss it or push it back.
Nested list of checkboxes in markdown is exactly how I organize my work days - I write it I every morning, and then review it every afternoon before I power down. It’s basically job-journaling, it helps fix everything in my head day-to-day.
This format is terrible for working with line-based tools; you need to go an unknown number of lines back to get the date or the time.
Although, TBH, the OP's suggestion of one-line-per-day puts too many items on the same ling. I would have gone with one line per event. Yes, there's more repetition, but you need no out-of-line context, you have to do a lot less parsing, and you can look at a fixed number of _columns_ and get the beginning of the description of each event, which is nicer for manual searching.
To me the biggest block for using any plain text format for daily stuff is I need a good mobile - laptop sync method that I can easily read / write and manage files on both mobile and laptop, does anyone have any recommendation? The best choice I can think right now is SimpleNote which I've been using for notes for a long time, but is there a way I can actually use .txt file instead of text been stored somewhere in a database.
If you find Syncthing too chatty and is a bit suspicious to what it connect to, you can really to set it up to only connect explicitely between nodes in a Tailscale network for example.
I don't like that week numbers are (documented as) mandatory. I wouldn't see myself grepping on a week number. I'd end up constantly looking up the correct week number in order to annotate each event properly, with no benefit in return. Then again, could write a macro/plugin thingy for one's editor of choice, to fill in the week number for you (ditto for day of week, which I would at least find quite useful, but which would similarly be a right pain to have to fill in manually all the time).
Also: claims to be "one thing per line", yet allows and encourages multiple events on one line (as long as they're on the same day). This is a calendar - is an event not the main "thing" we're dealing with?!
I use a template [1] that has the dates (including week numbers) there already. That way, I only need a text editor.
In my work, similar events happen on the same week numbers in different years. The importance of week numbers probably depends on your area of work.
For me, one thing is a day. That's also the context I need when reviewing and planning. But if I remember correctly, previous HN thread on calendar.txt had a suggestion where someone had an event-per-line format, if you prefer that.
In some ways it worked well, but there were a few drawbacks, and eventually I switched to native calendar programs on desktop and mobile.
Drawbacks I personally felt:
* In the text file, recurring tasks didn't show up when I looked into the future, such as to schedule an appointment.
* Calendar invites over email weren't integrated, so I had to enter and update those manually anyway. (Though one advantage over the native calendar programs I use now is that todo.txt doesn't force the appointment headline someone else wrote into my calendar view, and refuse to let me edit it in my local copy.)
* I had to keep editing dates on tasks manually, every day, for my "current day view" of top of the file to work with priorities.
* No visual calendar views with the tools I was using.
* No device sync with the tools I was using (though possible).
* There are only so many ways in which I was willing to be a weirdo at once, and this one didn't make the cut.
I don't discourage anyone from trying todo.txt or calendar.txt. Just a heads-up of some things you might want to find solutions/workarounds for.
Seems useful for very basic calendar requirements. I'm not seeing much about timezones or anything at all about DST so I'm guessing this format just ignores those for convenience. Saying "times are local to events" is great for physical events but when you're dealing with an international call, you probably want to specify that.
Using a full stop as a separator seems rather limiting, something less likely to appear in an event description such as a vertical pipe would make more sense. Now you'd need some kind of weird logic to write an event titled "read top 10 news.ycombinator.com articles". Using @ as a special character also means you can't store "email support@localhost.com" as an event title.
And, of course, everything is hard coded in English, using English style time notation.
This seems like a fine solution for a personal file format but everyone will probably have to modify it to fit their own needs. If I were to use it, I'd violate the "spec" all over the place by time and date notation alone. This could be fixed by adding some kind of header, but I doubt any full application will ever support a format like this so it's hardly a problem.
If I were to use this as a file format, I'd add headers to store things like language, default time zone, ltr vs rtl, and alter the separator characters. Adding something like a title, an author, and the moment of last edit might also be useful.
I'd personally also probably store events as separate, duplicate lines. That way, you can easily add an event to the bottom of the file without having to find/replace an existing date (or generate an entirely new line). Using basic POSIX tools you can easily get the events back to a single line without making scripts too difficult to read. Assuming culture and other headers match, you'd be able to import another calendar file by simply appending the event lines.
Interesting ideas for formalization and metadata, jeroendh. Some comments on those:
Calendar.txt is indeed a personal calendar. So feel free to violate the spec as much as you need or want to.
My main use for calendar.txt is editing with text editor, and thus, I have not given emphasis to automatic modification.
Time notation is ISO-8601 date and week number. In my view, ISO-8601 is an international standard and not tied to a specific country. I find it convenient to read and sort.
I use local time for physical events. For international calls, I just write down the timezone "13:00Z" or "11:00EET" (update: or mark it in my local time).
At-sign "@" for context was chosen to match todo.txt, as I also use that. As the calendar is personal, it does not need to be fully machine readble. But for your example on email addresses, you could still do it: @WORK email bob@example.com. The context starts with an at "@", email does not.
Full stop "." is easy to type on a cell phone. It's true that a rare char would be more suitable for automatic parsing.
I like text based formats for things. But I find that you need software to help with the maintenance and presentation of such things. Todo.txt and plain text accounting are two examples of this; sure you could edit the plain text but a software system just makes it better to use, especially on mobile.
With that in mind I don't see how this is a replacement for caldav. Sure looking at the plain text of a caldav file is worse, especially one generated by a computer, but at least all expected calendar functionality is included. Though the sprawling RFC is hardly simple to follow or implement.
I like this. It's a lot like Emacs `diary` system. Though, you can group multiple events under one day heading. I will say that I like how `grep`-able this is. As long as you know the rules, it's pretty easy to parse. You could probably whip up an alarm system in bash and cron/systemd and let it alert you like all those big-box programs do.
Exactly. Some people are looking at the format and thinking "well, this doesn't do much" but they're missing the point: it's a plain text format that plays very well with other common tools such that 'doing more' is trivial.
One thing I really would like in a calendar app is some sort of "change log", and this gets somewhat close to that, assuming you track the file in git.
For example, I recently scheduled a dentist appointment 6 months from now. Unless I scroll through the calendar, or specifically search for it, there is no easy way to find that I added that event.
As you guessed, roland35, I do track my calendar.txt in git.
One main benefit from git is also to work as an insurance against (user) errors, and make the whole process much more transparent. When I have used calendars with automatic synchronization, I would have enjoyed a "change log" to make sure that my timezones and meetings are not mistakenly modified by software.
For your dentist example, I would probably just use 'grep' or find in my text editor. After all, six months of days is very little text.
The first online store/cart I wrote (in php 3 or 4, around 2001), I didn't know sql so I worked backwards into inventing a database from scratch using text files. This was great for a couple years until someone put an asterisk into the name of a product. Asterisk was my row delimiter. lol.
ill tell you a funny, in January I gave my old boss (who passionately hates technology) my text file and told him he only forgot to pay two days in the (hectic) year. (I make one txt per year) It listed what work was done and with who.
His response was WOAH, I've always wanted this! He then send the whole thing to the printer and put it on the wall in his office. Then he added arrows to the days he forgot to pay using a ballpoint pen. He talked a bit about periods in the year and used his finger as a pointing device.
Sorry to be a Luddite, but isn’t this completely useless?
- one line per event, so good luck finding multi-day events like “Grandma is visiting”;
- rigid metadata (dates, week numbers, weekdays) stored right next to the editable data (events), so copy-pasting errors are inevitable;
- the most important feature of the real calendar software (reminders) is thrown out;
- grepping is really not how most people interact with a calendar.
If you’re ready to ditch reminders, attachments, locations, use the paper diary planner. At least it won’t let you screw the dates with botched copy-paste.
Update: also, sorting by date must be done manually, my god.
> one line per event, so good luck finding multi-day events like “Grandma is visiting”
The format allows for variable granularity and ranges. If Grandma were visiting for a week, it would be fine:
2021-02-20 w07
Right now, the range (start-end) can only be hours, but changing that could fulfil your requirement, e.g.
2012-02-20 w07 Mon-Fri Grandma is visiting
> grepping is really not how most people interact with a calendar.
I don't think the creator ever suggested for one minute that this is a calendar for "most people"! Most people don't use Linux, macOS, or a command line.
> sorting by date must be done manually, my god.
| sort
is not much of a hardship. At least it's possible, unlike a typical GUI app that doesn't support sort.
You're quite right, oneeyedpigeon. The main audience of calendar.txt are people who always have terminal open, and who are using grep, sort and similar all the time anyway.
I use +plustags for multiday and recurring events. So for each line +grandma is visiting, I would add the tag +grandma.
I take similar approach with my courses, +tt for pentesting (from the word in Finnish). I found that for me, creating and validating recurring and multiday events was easier for me. Of course, your mileage may vary.
Smikhanov, you found copy pasting challenging. For me, copy pasting from some dedicated calendar software was a challenge. Copy-pasting with calendar .txt makes it easier for me to keep date, week number, weekday and the event together. And your comment on paper planners was on the spot, I wanted to catch some of their benefits, transparency and reliability with calendar.txt.
I believe software is a form of literacy, not engineering. And I believe everyone should be literate it brings great benefits socially and individually
And if this works for him/her it’s a calendar on a piece of paper stuck to the fridge. Great, it works for them and some people might find it good for them too
Seriously, with the number of invites, slots, to juggle. Might be better to work again like a dev and with text files in an IDE. Would be funny to send invites with raising a PR. Merging, reviewing, ... what a beautiful mess.
I'm pretty sure the entire world uses ical files. It's a bit of an annoying format to parse, though. The calendar.txt file format seems to be made for people to interact with it directly through a terminal (which the target audience probably already had open).
I do something similar for daily notes for work. I have a shell alias `tdw` for `TODO work` which opens a YYYY-MM.md file in vim. Inside of that markdown file I use a vim macro that generates a date similar to what is shown in calendar.txt, where I take notes about what I am working on and what I have worked on. Here's ane example of what it looks like:
I kind of like the calendar.txt idea of prefixing every line with the date, because it makes grepping easier, but at the same time, it doesn't allow for sub-lists and more detailed notes about what was worked on. It hasn't been a big enough problem to deal with though, because of things like `grep -i -B10 encabulator`The vim macro I use is:
As a file format, this is just fine, but I feel like there's some conflation between a file format and software meant to interact with that format.
I use plain text accounting for my business, and it's lovely to be able to enter bookkeeping data with a plain text editor and keep it all under version control, but the next step is using a program such as hledger or beancount to work with that data.
I'd love to work with plain text calendar software, but it would still need to do things such as provide a mechanism to work on my desktop and mobile device. It would need to handle recurring events automatically, and it would need to allow me to invite others to events and ideally to track when they've accepted or rejected my invites.
I'd need to be able to update, cancel or propose to move events in such a way that others would be updated.
I wish I knew of a good command line tool to interact with CalDav or similar servers, or that I could maintain my calendar in a file format and then handle the synchronization automatically.
Maybe calendar.txt could play a role in that, but on its own, it's not quite enough for me.
This is definitely in the camp of oversimplifying by missing the whole problem domain.
For reminders and other automated actions, pydry suggested "orgzly revived with org mode"; and kruffalon suggested 'remind'. I have not tried those, but they might be better options for notifications and reminding than calendar.txt.
I use calendar.txt on a cell phone with Markor text editor. For my desktop, I just use micro editor on terminal, the same I use for most text editing tasks.
Bookkeeping using plain text files sounds both interesting and challenging.
> Bookkeeping using plain text files sounds both interesting and challenging.
It has quite a bit of a following; I personally would never switch back to some more "complete" application. I believe all the most popular implementations are listed here: https://plaintextaccounting.org/
So many tempting options...
Can you recommend a tool and open your accounting workflow, marttt?
Are there any pain points, like filling tax forms or handling travel paperwork?
I’ve used this tool before for caldav: https://github.com/pimutils/khal
Nice idea, but the calendar format is a bit verbose for my taste. Week number is something I would have to look up constantly and surely get wrong more than once.
If you want to follow UNIX philosophy, why don't you write an augmenter/converter tool `caug` that adds "computed" information such as week number, weekday or even relative date?
That was my first thought too; I often use Google Sheets/Excel as a lightweight todo calendar, and I'll make formulas to calculate week-of-year and day-of-week. These lists are so lightweight and adhoc that having to do that kind of calculation would be enough friction to not maintain the lists after a short period
I use a template [1] that includes week numbers.
With some traditional GUI calendar software, I was often hunting and miscopying week numbers. Some software also had a weird (non ISO-8601) idea of week numbers.
In case you need calendar.txt after 2033, I wrote a small tool [2] to generate more templates.
[1] https://terokarvinen.com/2021/calendar-txt/calendar-txt-unti...
[2] https://terokarvinen.com/2021/calendar-txt/calendartxt-gener...
> Unix philosophy. It's one day, one line.
The Unix philosophy is often recited as "do one thing, and do it well". This does one thing, but doesn't do it well at all.
Without any explanation, this comment isn't particularly productive. Can you explain how it doesn't do it well?
I am also sceptical.
It's conflating a format for recording calendars with a syntax the user needs to write.
That syntax looks quite brittle and not very intuitive. One day = one line would get unwieldy fast. It doesn't localise well and there's no obvious way to implement recurring events beyond daily actions. (From what I can see at least?)
You could build a client on top of that but then, you lose the benefit.
It's a neat idea and it's good to see someone share a simple concept that works for them. But I don't see it working for most people.
I would say it doesn't do anything. It may has well defined what should be done - but doing it well and correctly is burdened upon the user.
It even says:
> Unix philosophy. It's one day, one line. You can grep (only show lines).
Surprisingly, grep is able to output several lines, so even if you were to use a (say) more sensible format of one line per event, grep could still output all lines, and display them.
I like this, but need more detail in my log and have too many things in a given day to have them all on a line. Had the following idea, and will try it out at some point. Call it calendar.md
Use calendar.txt format and method with the following changes:
1) Use markdown, with a top level heading of Calendar (so inclusion is easier) and the portion
2) Use :tag: instead of +tag. Tags can be run together (:tag:tag2:). This helps with Org mode compatibility
3) Third level heading for each event in day, following same format as calendar.txt
4) text under heading is for notes about the event
5) Searching and seeing info on event in day, or summary about day is no longer easy with grep. This is the biggest drawback from not using calendar.txt. Overcome by writing a tool mgrep that is specifically designed to search markdown files in a Markdown aware way (search headings or specific level of headings, show all headings under matching heading or just one level under, show all content under matching headings, search text and show either lines or section text is in optionally along with ancestry of headings).
6) Create CalendarMDMode, minor mode designed to facilitate calendar.md use and editing within Emacs, requires OrgMode, things like shortcuts for new date, new event, in-editor use of mgrep, etc.
7) Attempt to add CalendarMD support to Helix, which is my daily notes editor, using the as-yet unlanded Scheme based plugin system (see https://github.com/helix-editor/helix/pull/8675 )
I especially like your 'mgrep', please do write it!
I have considered similar tools that make use of MarkDown syntax, I feel that there are many tools waiting to be written here.
I’m skeptical about convenient plain text is, compared to more structured formats, once we try to encode even more of the conveniences we get out of current calendaring (e.g. time zone shifting, notes of indefinite length, events that last the whole day, repeated events…)
There are a few more structured formats for calendaring that share the virtues of their workflows: if we used JSON, would jq be a UNIXy tool? What about sqllite and commandline queries? Both would be much more easier for my overloaded mind - especially when parsing records - without adding more inherent complexity beyond a sufficiently overloaded raw text calendar.
I created a super-simple CalDav-esque web endpoint in my personal website that receives HTTP requests from a command line tool, stores the calendar events, and then returns them as a dynamic ICS file. Then, I use Apple’s Calendar app to subscribe to a “hidden” URL and iCloud automatically distributes the subscription to all my devices.
It sounds super dumb but it works so well.
The main feature is that I can categorize the events (personal, family, work, friends, etc.) and share individual URL’s with other people. Admitedly, I didn’t try solving this problem with Google Calendar, Apple Calendar, or any other calendar service, mostly because I wanted to own my data and also learn a bit more about CalDav itself.
This is close to what I want. I manage all my calendars in radical caldav server and want a sharable calendar that just shows the empty spots between all calendars with minimal detail fo easy scheduling.
My format used to be as follows:
This worked really well for me and was easily searchable. One benefit would be that it is easily trackable in Git.These days I have a little A6 lined notebook and manually list tasks there. Each page is a new day and the tasks are listed similarly. The only modification is that sometimes I put some letters to theme a task, i.e.:
I use a small paper planner that I keep in my pocket at (nearly) all times. People are taken aback and ask why I don't use something more modern, but why should I? This works better, for me, than anything else I ever tried.
It's unfair to computers how well paper planners worked. Among with todo.txt, paper calendars were an inspiration and a benchmark for writing calendar.txt.
This is a much nicer format than the one in the linked article.
I think my approach would be to generate a file in Markdown, then import that into a good Markdown editor. You could generate it each week or month from a template, making it easier to add repeating tasks like exercise and dog walking.
I think the format I suggested would parse in markdown, but I created it pre-markdown.
For me the best parts are:
1. You could write a parser very quickly.
2. It's very easy to edit and add to as a human.
3. It can easily be tracked in git or via a diff-based tool.
I did already think about the repetitive tasks, a long time ago I used to have a tool that would look at the past tasks and recommend future tasks (with appropriate distributions). One example was booking a dentist appointment every 6 months, even if I forgot to schedule something it would remind me to book one in, dismiss it or push it back.
Nested list of checkboxes in markdown is exactly how I organize my work days - I write it I every morning, and then review it every afternoon before I power down. It’s basically job-journaling, it helps fix everything in my head day-to-day.
This format is terrible for working with line-based tools; you need to go an unknown number of lines back to get the date or the time.
Although, TBH, the OP's suggestion of one-line-per-day puts too many items on the same ling. I would have gone with one line per event. Yes, there's more repetition, but you need no out-of-line context, you have to do a lot less parsing, and you can look at a fixed number of _columns_ and get the beginning of the description of each event, which is nicer for manual searching.
I think it's somewhat passable with line-based tools, i.e. you could easily use sed to match a range [1].
I think that it's far more important that it is human readable, if it becomes too tricky to edit manually, then just go with a database.
[1] https://unix.stackexchange.com/a/236754
To me the biggest block for using any plain text format for daily stuff is I need a good mobile - laptop sync method that I can easily read / write and manage files on both mobile and laptop, does anyone have any recommendation? The best choice I can think right now is SimpleNote which I've been using for notes for a long time, but is there a way I can actually use .txt file instead of text been stored somewhere in a database.
I recommend https://syncthing.net/
Works with all file formats, from photos and movies to text files. Cross platform: Linux, Windows, Android, probably also Mac and BSD.
Update: And it's end-to-end encrypted and free, open-source software.
If you find Syncthing too chatty and is a bit suspicious to what it connect to, you can really to set it up to only connect explicitely between nodes in a Tailscale network for example.
I use my Gmail drafts as permanent, in-sync notes (with subject as the title of each note) Why?
- No extra app needed
- Keeps them quite hidden / private / secure
- Always easy access (I always have emails open)
- In sync with different devices
I just use SyncThing.
I don't like that week numbers are (documented as) mandatory. I wouldn't see myself grepping on a week number. I'd end up constantly looking up the correct week number in order to annotate each event properly, with no benefit in return. Then again, could write a macro/plugin thingy for one's editor of choice, to fill in the week number for you (ditto for day of week, which I would at least find quite useful, but which would similarly be a right pain to have to fill in manually all the time).
Also: claims to be "one thing per line", yet allows and encourages multiple events on one line (as long as they're on the same day). This is a calendar - is an event not the main "thing" we're dealing with?!
I use a template [1] that has the dates (including week numbers) there already. That way, I only need a text editor.
In my work, similar events happen on the same week numbers in different years. The importance of week numbers probably depends on your area of work.
For me, one thing is a day. That's also the context I need when reviewing and planning. But if I remember correctly, previous HN thread on calendar.txt had a suggestion where someone had an event-per-line format, if you prefer that.
[1] https://terokarvinen.com/2021/calendar-txt/calendar-txt-unti...
For a few years, I evolved a slightly-modified Todo.txt format for this purpose, to represent both tasks and appointments.
http://todotxt.org/
https://www.neilvandyke.org/todotxt/
In some ways it worked well, but there were a few drawbacks, and eventually I switched to native calendar programs on desktop and mobile.
Drawbacks I personally felt:
* In the text file, recurring tasks didn't show up when I looked into the future, such as to schedule an appointment.
* Calendar invites over email weren't integrated, so I had to enter and update those manually anyway. (Though one advantage over the native calendar programs I use now is that todo.txt doesn't force the appointment headline someone else wrote into my calendar view, and refuse to let me edit it in my local copy.)
* I had to keep editing dates on tasks manually, every day, for my "current day view" of top of the file to work with priorities.
* No visual calendar views with the tools I was using.
* No device sync with the tools I was using (though possible).
* There are only so many ways in which I was willing to be a weirdo at once, and this one didn't make the cut.
I don't discourage anyone from trying todo.txt or calendar.txt. Just a heads-up of some things you might want to find solutions/workarounds for.
Seems useful for very basic calendar requirements. I'm not seeing much about timezones or anything at all about DST so I'm guessing this format just ignores those for convenience. Saying "times are local to events" is great for physical events but when you're dealing with an international call, you probably want to specify that.
Using a full stop as a separator seems rather limiting, something less likely to appear in an event description such as a vertical pipe would make more sense. Now you'd need some kind of weird logic to write an event titled "read top 10 news.ycombinator.com articles". Using @ as a special character also means you can't store "email support@localhost.com" as an event title.
And, of course, everything is hard coded in English, using English style time notation.
This seems like a fine solution for a personal file format but everyone will probably have to modify it to fit their own needs. If I were to use it, I'd violate the "spec" all over the place by time and date notation alone. This could be fixed by adding some kind of header, but I doubt any full application will ever support a format like this so it's hardly a problem.
If I were to use this as a file format, I'd add headers to store things like language, default time zone, ltr vs rtl, and alter the separator characters. Adding something like a title, an author, and the moment of last edit might also be useful.
I'd personally also probably store events as separate, duplicate lines. That way, you can easily add an event to the bottom of the file without having to find/replace an existing date (or generate an entirely new line). Using basic POSIX tools you can easily get the events back to a single line without making scripts too difficult to read. Assuming culture and other headers match, you'd be able to import another calendar file by simply appending the event lines.
Interesting ideas for formalization and metadata, jeroendh. Some comments on those:
Calendar.txt is indeed a personal calendar. So feel free to violate the spec as much as you need or want to. My main use for calendar.txt is editing with text editor, and thus, I have not given emphasis to automatic modification.
Time notation is ISO-8601 date and week number. In my view, ISO-8601 is an international standard and not tied to a specific country. I find it convenient to read and sort.
I use local time for physical events. For international calls, I just write down the timezone "13:00Z" or "11:00EET" (update: or mark it in my local time).
At-sign "@" for context was chosen to match todo.txt, as I also use that. As the calendar is personal, it does not need to be fully machine readble. But for your example on email addresses, you could still do it: @WORK email bob@example.com. The context starts with an at "@", email does not.
Full stop "." is easy to type on a cell phone. It's true that a rare char would be more suitable for automatic parsing.
Thanks for the ideas!
I like text based formats for things. But I find that you need software to help with the maintenance and presentation of such things. Todo.txt and plain text accounting are two examples of this; sure you could edit the plain text but a software system just makes it better to use, especially on mobile.
With that in mind I don't see how this is a replacement for caldav. Sure looking at the plain text of a caldav file is worse, especially one generated by a computer, but at least all expected calendar functionality is included. Though the sprawling RFC is hardly simple to follow or implement.
Emacs got you covered, my friend, no reason to reinvent the wheel:
https://www.gnu.org/software/emacs/manual/html_node/emacs/Fo...
I like this. It's a lot like Emacs `diary` system. Though, you can group multiple events under one day heading. I will say that I like how `grep`-able this is. As long as you know the rules, it's pretty easy to parse. You could probably whip up an alarm system in bash and cron/systemd and let it alert you like all those big-box programs do.
Such an alarm system would be interesting (and even sounds feasible), even though I don't use reminders myself.
Exactly. Some people are looking at the format and thinking "well, this doesn't do much" but they're missing the point: it's a plain text format that plays very well with other common tools such that 'doing more' is trivial.
One thing I really would like in a calendar app is some sort of "change log", and this gets somewhat close to that, assuming you track the file in git.
For example, I recently scheduled a dentist appointment 6 months from now. Unless I scroll through the calendar, or specifically search for it, there is no easy way to find that I added that event.
As you guessed, roland35, I do track my calendar.txt in git.
One main benefit from git is also to work as an insurance against (user) errors, and make the whole process much more transparent. When I have used calendars with automatic synchronization, I would have enjoyed a "change log" to make sure that my timezones and meetings are not mistakenly modified by software.
For your dentist example, I would probably just use 'grep' or find in my text editor. After all, six months of days is very little text.
The first online store/cart I wrote (in php 3 or 4, around 2001), I didn't know sql so I worked backwards into inventing a database from scratch using text files. This was great for a couple years until someone put an asterisk into the name of a product. Asterisk was my row delimiter. lol.
This seems like it'd be much more practical as a CSV file.
One event per line might just be better.
`YY-MM-DD:HH:MMa (Optional repeat cron definition) "Event string"`
A very similar idea and philosophy - http://todotxt.org
I can recommend todo.txt, as I've been using it for years. Todo.txt was one of the inspirations to create calendar.txt.
It also works nicely together with calendar.txt for me. I can 'grep' trough both to see all todos and events related to a project or a +tag.
ill tell you a funny, in January I gave my old boss (who passionately hates technology) my text file and told him he only forgot to pay two days in the (hectic) year. (I make one txt per year) It listed what work was done and with who.
His response was WOAH, I've always wanted this! He then send the whole thing to the printer and put it on the wall in his office. Then he added arrows to the days he forgot to pay using a ballpoint pen. He talked a bit about periods in the year and used his finger as a pointing device.
Previously:
3 days ago, 7 points, 0 comments https://news.ycombinator.com/item?id=43169019
1004 days ago, 202 points, 93 comments https://news.ycombinator.com/item?id=31574125
Have you looked into remind[0] while working on this?
There might be value in checking that out.
Personally I haven't used it in years, but the latest release is from this year so it seems active.
---- [0] https://dianne.skoll.ca/projects/remind/
I love it but I believe I am deeper in that rabbit hole.
I just create files in a folder with the `yyyy-MM-dd-hh:mm` format. I use `XX` for recurring events.
I use `at` for reminders/notifications.
This is an idea so basic, yet so good, that it should be general knowledge already.
I will try to include it in my custom OS from scratch. Should be simple, right?
Fix the bug where it starts in 2021
Sorry to be a Luddite, but isn’t this completely useless?
- one line per event, so good luck finding multi-day events like “Grandma is visiting”;
- rigid metadata (dates, week numbers, weekdays) stored right next to the editable data (events), so copy-pasting errors are inevitable;
- the most important feature of the real calendar software (reminders) is thrown out;
- grepping is really not how most people interact with a calendar.
If you’re ready to ditch reminders, attachments, locations, use the paper diary planner. At least it won’t let you screw the dates with botched copy-paste.
Update: also, sorting by date must be done manually, my god.
The format is probably ok for non-edit logging like journalling or recording something like weight loss.
> one line per event, so good luck finding multi-day events like “Grandma is visiting”
The format allows for variable granularity and ranges. If Grandma were visiting for a week, it would be fine:
Right now, the range (start-end) can only be hours, but changing that could fulfil your requirement, e.g. > grepping is really not how most people interact with a calendar.I don't think the creator ever suggested for one minute that this is a calendar for "most people"! Most people don't use Linux, macOS, or a command line.
> sorting by date must be done manually, my god.
is not much of a hardship. At least it's possible, unlike a typical GUI app that doesn't support sort.You're quite right, oneeyedpigeon. The main audience of calendar.txt are people who always have terminal open, and who are using grep, sort and similar all the time anyway.
I use +plustags for multiday and recurring events. So for each line +grandma is visiting, I would add the tag +grandma.
I take similar approach with my courses, +tt for pentesting (from the word in Finnish). I found that for me, creating and validating recurring and multiday events was easier for me. Of course, your mileage may vary.
Smikhanov, you found copy pasting challenging. For me, copy pasting from some dedicated calendar software was a challenge. Copy-pasting with calendar .txt makes it easier for me to keep date, week number, weekday and the event together. And your comment on paper planners was on the spot, I wanted to catch some of their benefits, transparency and reliability with calendar.txt.
Oh I agree … but
I believe software is a form of literacy, not engineering. And I believe everyone should be literate it brings great benefits socially and individually
And if this works for him/her it’s a calendar on a piece of paper stuck to the fridge. Great, it works for them and some people might find it good for them too
But yeah.
“One day I will get organisssseed”
Seriously, with the number of invites, slots, to juggle. Might be better to work again like a dev and with text files in an IDE. Would be funny to send invites with raising a PR. Merging, reviewing, ... what a beautiful mess.
Plain text is fine as a backing format...but not as an interface for something more complicated than text or lists.
Editing this on mobile sounds very annoying.
Thank you for bringing up calendar.txt. My homepage is feeling the hug. In the meanwhile:
https://web.archive.org/web/20250216110151/https://terokarvi...
Now my homepage should answer in under 300 ms again. Thanks for visiting!
orgzly revived with org mode
It's like this, but better. I actually get notifications from my calendar text file. I can set some of them as alarms.
its https://xkcd.com/927/ all over again
Are there that many calendar formats? I thought iCal was by far the most ubiquitous. I've heard of jCal as well but never seen it in the wild.
I'm pretty sure the entire world uses ical files. It's a bit of an annoying format to parse, though. The calendar.txt file format seems to be made for people to interact with it directly through a terminal (which the target audience probably already had open).
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