Please, everyone, use a single format at all times in your systems. I don't really care what it is, though I'm fond of `2021-01-14T06:28:08Z` because it's unambiguous. But don't just say "use ISO 8601", it's far too vague and you'll inevitably have variations.
* `2021-W02` means the second (ISO) week of 2021. Perfectly valid and used in a lot of planning.
* `--01-14` - I'm assuming this is a recurring date: every 14 Jan for every year
* `--1013` - at 1PM every 10th of the month? Guessing here
I believe ISO 8601 is a ISO codification of a DIN standard, and based on other standards processes I'm guessing some German manufacturing companies were the only ones who bothered showing up, so their internal software practices were encoded into the spec because no-one else cared..
Often the biggest entity will end up accidentally forcing their practices, sometimes sub-optimal, to entire organizations, simply by having the manpower to show up to meetings.
(`--01-14` is Jan 14 in any year, the last dash is "optional").
The "duration" (`P`) and "repetition" (`R`) syntax is also pretty wild.
https://docs.python.org/3/library/datetime.html#datetime.dat...
https://github.com/elastic/logstash/blob/v1.4.2/patterns/gro...