I have 10 staff and need to organise a spreadsheet showing their leave entitlement.

Everyone's leave starts on 1 Jan, is there a formula I can use so that it automatically adds accrued leave at the rate of 1.8 days on the first of every month

EG: On 1st Jan it should show 1.8 days then on 1st Feb it automatically changes to 3.6 then on 1 Mar it should change again to 5.4 etc, etc

Thank you