They stopped Sunday special delivery in 1885 so I hear.
You know, I’ve often wondered why the PO hasn’t taken up Sunday delivery. Originally Sunday was a day off because of religious reasons - per God, Sunday is to be a day of rest.
It seems to me that for any government offices to not function on Sundays is establishment of religion and should be abolished. Open up all government offices on Saturdays and Sundays. Let the workers pick, by seniority, what days off they want. We pay to have the lights and so forth on over the weekends anyway. The other benefit, besides avoiding the dastardly appearance of establishment of religion, is that the rest of us wouldn’t have to take time off work from our jobs in the productive private sector in order to visit governmental offices to straighten out all the errors they make in their myriad taxation schemes and regulatory requirements.