Help with formulas for entilement days and service

Hi all

I am struggling to make my holiday logging spreadsheet working fully. i am struggling to get the entitlement days in particular to do the following please can you help? Its beggining to mess with my mind lol
any help and advice greatly appreciated,

Holiday Entitlement Days (bank holidays are given, but not logged so to speak)
New starters receive a percentage of the 1st year?s holiday entitlement (20 days) until the 1st of January the upcoming year. Once into the new year the receives 20 days but planner needs to show the reduced days in the entitlement column until into the following year.
First year?s holiday starts at 20 days, then increases by 1 day up to a maximum of 25 days after 5 years of service. Then after 10 years you receive a further day taking you up to 26 days, after 20 years another day up to a maximum of 27 entitlement days. a years holiday runs 1st jan to following 1st of jan.

In exceptional circumstances
There is a column for additional days granted (at interview stage) these are added to the entitlement figure but can only take you up to a maximum of the 25 days. For example if you start with 20 days but are granted an extra two days to your entitlement the first full year would grant 22 days that would increase to a maximum of the 25 days. Every year gaining a additional day. These people get to the maximum 25 days quicker than others.



regards

stephen