backdate

2.~ sth使（付款等）在较早的日期开始生效to make sth, especially a payment, take effect from an earlier date

1.把发生的日期说成[写成]比实际的更早

2.追溯至(过去某时) back the salary increase three months 加薪自三个月前起算

1.to make a rule or law start to be effective from a date in the past

2.to write a date on a document or check that is earlier than the date when it was really written