How Early In The Day For A First Day Cover!

How many have seen a First Day Cover with a postmark this early in the morning -- at 1:00 AM on the first day of issue -- October 19, 1929?

In the UK, for a few years, it was possible to have a FDC postmarked with the PREVIOUS day's date quite legitimately. That's a whole day early according to the postmark

How was it done? New issue stamps were on sale at midnight at all-night Post Offices in London. The covers were then posted at stations where mail was due to be picked up and processed by a Traveling Post Office on the way to London. The datestamp used on the TPO's was the date of departure and was not changed after midnight.

I suppose that might have been possible in the UK, but back in 1929 in the US, stamps weren't available nationwide on the first day of issue. You had to send requests to the first day of issue post office and they affixed the stamps to self addressed covers for postmarking. Therefore, a 1:00 AM postmark is quite unusual (I think).

Anyway, if you want to consider the other extreme, here's another US First Day Cover, this time with a late date stamp -- 11:30 PM and on New Year's Day (January 1, 1932). I think this would have been about the latest date stamp possible for a First Day Cover!