There are a few posts about this, so apologies for the new one. But here in the UK holiday is best calculated in days and not hours.
Staff are allowed 5.6 weeks holiday per year, you multiply this by how many days they work a week 1-5 and that gives you their holiday days.
so employers and employees can see clearly how much holiday they have to use in a given year.
when they book a day off it will knock the value down by 1 and when it comes to that date of leave, it will automatically apply their "Leave averaging" figure linked to "1day" (which is currently found under employee profiles so should be fairly easy to link up)
and then that can happen if they book 2 or more days off as well, it takes 2 or more off their total balance, then their leave averaging is automatically applied on each day.
it shows employers and employees how many days they left that they are entitled too, everyone is happy, staff don't take too many days off in a year, and can understand how to spread them out easier.
If each staff is linked to their own profile leave averaging figure rather than a fixed across the board figure of "hours in a day" it means a more autonomous software and less leg work for the employer, which is what we pay for.