Can a Maths Whizz help me?

How to calculate holiday entitlement for the employee with 5.5 years as at 1st April?
Holiday entitlement is 15 days per annum, pro-rata. It increases annually to a maximum of 19 days after 9 years service as follows:
Complete years service as at 1st April ——-> No of Holiday
1 to 5 years ——-> 15 days
6 year ——-> 16 days
7 years ——-> 17 days
8 years ——-> 18 days
9 years and above ——-> 19 days
Answer #1
A trick question ?
15 and a half days.
Holiday entitlement isn’t usually carried forward to the next fiscal year.
Answer #2
Surely it doesn’t matter if you are 5 years, to 5 years and 11 months, it will stay as 15 days until you get to the full 6 years
That’s if i’m reading this right