Work Days excluding Leave as an average

Hello Experts, in need of assistance on how to create a DAX formular to reduce the number of work days & hours, based on an average of leave per mth/ yr over actual......

My scenario is I have multiple employees (1500) working across multiple projects (6000+ pa) nationally (different public holiday dates) and various types of leave, e.g. 4wks annual, careers leave, volunteer leave, sick leave, etc etc.....Ans of course none of my data sources actually align or provide me with the necessary data.

So, to keep things simple, I am looking for your expert advice on a DAX solution/ formular to average out all potential leave = 42 days per calendar year @ 3.5 days per month as non work days

I have a 'Date Table' that has a measure based on work days Being based on Mon to Fri & another Colin calculating work days * 7.35 (hrs worked per day)

What I now need to include is leave work days, e.g. 23days = 19.5days & hours are 169 to 144

Any and all advice greatly appreciated