I am trying to figure out my holiday (vacation) entitlement. Can somebody please tell me if I am right?
I get $27$ days holiday plus the bank holidays (public holidays). My work year is $1$st of April to 31st of March. Due to Easter moving about that means this year I get $7$ days as bank holidays. In total this year I get $34$ days holiday entitlement
If I worked full time I would do $7.5$ hours per day and work $5$ days per week $= 37.5$ hours per week. $34$ holidays days $\times 7.5$ hours a day $= 255$ hours holiday entitlement. If I was full time every time I take holiday day I would lose $7.5$ hours/$1$ day from my holiday entitlement.
I don’t work full time. I do $18.45$ hours per week which is half a week’s work. I don’t work $2.5$ days though. I work $3$ days per week and do $6.45$ hours a day.
Based on that information am I correct in saying the following?
This year I get $127.5$ hours holiday entitlement (half of a full time worker). Every time I take a holiday day I take off $6.15$ hours from my holiday entitlement
Or should it simply be:
I get $34$ days holiday entitlement. Every time I take a holiday day I just take a day off my holiday entitlement.
I'm fairly certain that the policy on this depends on your employer. You should probably consult your HR department.
That said, let's talk about the math: some of your assumptions appear strange to me. You say that full time is $7.5$ hours per day and $5$ days per week (which would be different from the common standard of $40$ hours per week) but then you also say that your "half-time" appointment is $18.45$ hours per week. $18.45$ hours per week is $49.2\%$ of $37.5$ - do you mean $18.75$, which would be $18$ hours and $45$ minutes? Relatedly, I think your "$6.45$ hours per day" should be "$6$ hours and $15$ minutes per day" (one-third of $18.75$ hours), which is $6.25$ hours per day. Recall that there are only $60$ minutes in an hour. In which case, assuming that your employer measures holiday time hourly, you should have a total of $127.5$ holiday hours from which you should deduct $6.25$ every time you take a day off. That's approximately $20$ days off ($20$ days with about three additional hours left over).
However, I have never had an employer that counted public holidays in terms of hours off - again, you should talk to your employer's HR department or someone else directly familiar with your employer's policies.