backdate
/ˌbækˈdeɪt ˌबैक्ˈडेट्/ verb [T] to make a document, a cheque or a payment take effect from an earlier date चेक आदि दस्तावेज़ को पिछली तारीख़ से प्रभावी बनाना
The pay rise will be backdated to 1 April.