USPS delivering on Sundays? Out here they're open from 8:30-12:30 (lunch you know) then 1:30-3:30 on weekdays. 8:30-10:30 Saturdays.
We're living large. more first world problems
The way I understand it, they only deliver large packages on Sunday.
EDIT: Found this from 2013. Guess it's been happening for years. https://www.uspsoig.gov/blog/no-more-day-rest-postal-package-delivery