[...] Lenders are frequently just as happy to receive a payment on the 31st as they are on the 1st, especially if they receive a late fee of some sort if received on the 31st. [...]
If I remember correctly it took "a few more days" (than 1), and OP
did not pay the "late fee" (last time I checked)...
Further more, OP states he;
[...] always was in contact of the lender [...]
and - again, if I remember correctly - this was
not the case: IMHO if you're going to be late you should contact the lender
in advance, not
after the fact...