Okay so I thought I had realistic expectations of Atlassian products, but they just keep finding new and appalling ways to surprise me.

At least the error message tells you exactly what kind of ass-backwards decisions they've made so you can adjust, I guess.

Update: it gets worse!!

The placeholder text uses hyphens as separators, but the calendar control inserts slashes.

So what happens if you literally type in the suggested placeholder text? Surely they wouldn't suggest an invalid format?

If you guessed "of course they would" congratulations! You have the correct amount of faith in Atlassian's quality control! Blisteringly cursed software design, stratospheric levels of dgaf.

Bonus: yes, the placeholder dates are in January *2012*, and I would not be surprised in the least if that means this code hasn't been updated in over a decade.

Welp, @avocatto couldn't just let this one lie, and observed that with two-digit years, you've got Y2K problems, right?

You sure do. So I dug in: I figured they probably implemented the solution you use if for some reason HAVE to deal with two-digit dates (which they don't, but chose to anyway).

You just pick a number, and assume any dates before that number are 20xx, and after are 19xx. For something like JIRA where you're not really recording historical data, you can probably get away with this. You're not gonna have tickets opened before, like, 1980, maybe pick 1970 cause it's the epoch, there, you're future proof for 50 years.

So I went to test, and was surprised when 50 was interpreted as 1950...and a few astonished trials later: jimminy cricket on a bobsled, they chose nineteen-FORTY-TWO as the first year to assume is 19xx

I really, really wish I were making this up because I am at a loss as to how you even begin to end up here. Stumped.