backdate

• back-date
• back date

From back +‎ date.

backdate (third-person singular simple present backdates, present participle backdating, simple past and past participle backdated)

1. To give or assign a date to a document that is earlier than the current or true date.

   Synonyms: antedate; see also Thesaurus:backdate

backdate (plural backdates)

1. An assigned date that is earlier than the current or true date.
   • 2000, Jack Stewart, Hurricane, page 50:

     The backdates on the clearance forms made the little man's papers worthless […]