Three days and an hour more than you think, because it's the weekend, and an extra day because the public holiday for tomorrow may or not be a working day. Oh and there was a timezone change.
And last year someone else's code failed on 30 December 2019, so I had a pretty good idea where to look.
Still need to fix a bug in code written only yesteryear because the 1st of July wasn't on a Monday this year, but I decided to snooze that test failure ... it'll work fine again in 9 years.