This question is now being asked a lot. It should be:
- Payday on 24/12/2019 is available on 23/12/2019 after 4pm.
- Payday on 27/12/2019 is available on 24/12/2019 after 4pm.
- Payday on 30/12/2019 is available on 27/12/2019 after 4pm.
https://community.monzo.com/t/payments-over-christmas/86758/2?u=chapuys