whoever wrote the code for NYC's vaccine scheduling website fucked up because the "day-of" health screening you're supposed to fill out the morning of your appointment becomes available only at midnight if you have a 1am appointment, which is entirely non-obvious to most people
if you try to access the screening hours before it gives you a very confusing "sorry, we couldn't find your appointment in our system" error, which is guaranteed to make quite a few people confused and nervous. come on, for the purposes of UX, 1am is still the same day.