Earlier this week I was thinking through some weekly routines and got to wondering how weeks get numbered. Like, I’m writing this in Week 31, but what system’s used to calculate that?
So I found the Wikipedia page on ISO week dates, which was fascinating. I have many thoughts.
the basic idea
While I went for a simple week numbering system, it turns out that ISO 8601 defined a full way of telling the dates based on the week of the year and the day of the year. Today, 2024-08-04 in standard date-keeping, is 2024-W31-7 under the week date system.
At first this just looks like some weird alternate way to tell time, but there’s a crucial element there: it has no reliance on months. Week dates completely ignore the weird, inconsistent concept of months the Gregorian calendar emphasizes so strongly.
Under this system:
- the year is always a full number of weeks, starting on Monday and ending on Sunday
- the date tells you what the weekday is
- it’s almost a perennial calendar, with the exception of leap weeks (see below)
- the weeks still line up with the standard Gregorian calendar, so both can be used side-by-side without issue
drawbacks
One thing you might have been wondering is how this system handles the beginning and end of the year. Well, the first week of the year is the full week containing the first Thursday, so if January 1st of the year is a Friday, the first few days of January are considered part of the previous year. Similarly, if the first day of the year is a Wednesday, the last two days of the previous December are considered part of the next year.
It’s a little strange in that regard. But for most of the year, it seems to work flawlessly with very few drawbacks.
One other downside: it’s still dependent on the Gregorian calendar; the length of the year is dependent on the main calendar others use, not on any intrinsic numbering system, which makes it a little odd. But that’s also the source of a main upside of the system, the compatibility with normal datekeeping.
If you’re willing to waive that compatibility, Rick McCarty has published a very similar system.
my thoughts
I really like the concept of this system and want to learn to use it.
I could see it used for:
- budgeting
- journalling
- keeping track of a personal routine
- goal setting
It’s not so useful for:
- handling deadlines in school (since they’re given to me as Gregorian dates)
- scheduling meetings with other people (since they don’t usually know this system)
I’m going to at least start journalling this way, and perhaps making week notes in this system, as I was inspired to do by one of Tracy Durnell’s recent posts on how she uses them, which actually sent me down this whole rabbit hole in the first place.
There’s a chance I might publish some things here notated with week dates; if so I’ll link back to this post to explain for people who missed it.
I’d love to hear your thoughts; my email is below!
