Usage patterns
〈物〉に日付を書くto write the date on something
I forgot to write the date on the letter.
日付が変わるfor the date to change (usually at midnight)
I want to finish work before the date changes.
日付を確認するto check/confirm the date
Please check the date before making a reservation.
日付を入れるto put a date on (a document, stamp, etc.)
You need to put a date on the contract.
日付を遡るto backdate (a document)
That document was backdated.