if this ain't a zap from you, then i am not here

This is the right answer

lexicographical sorting ftw

Easily sorted as a string. Easy to sub string out year or year and month for filtering. In a folder with dates you can sort even if the modified or created dates are wrong. So much value in year month day.

ISO8601 all the way baby. I use it everywhere I can in the small hope it becomes the new normal.

time.RFC3339

That's the only way to properly date.

YYYYMMDD - I don't like hyphens.