といっても、最後の集荷が終わったあとくらいまでですけどね。
午前1時前後だったかな？
日付けを交換すると、きちんと記録しないといけないので戻すことはできません。
やれなくはないけど、やったら多分罰則があるんじゃないかなーと。

あとは自分あてに届いた郵便物はその場で抜けるので、運が良ければ速達並みの速さで受け取れます(笑)
今はどうか知りませんけど！

That would be after the last mail pickup was done, though. I think it was right around 1:00 a.m.?

When you change out the date, you have to record it properly, so you can't change it back. Well, not that you couldn't, but there'd probably be penalties if you did.

Also, you could pass through mail addressed to you right on the spot, so if you were lucky, you could receive it as fast as you would get Express Mail! :-) I don't know what it's like these days, though!