How is holiday entitlement calculated in hours for someone starting part way through the holiday year if they do different hours each day? For example someone working 3 days a week 22.5 hours in total, but the working hours per day are not the same each day. I took the full entitlement for the year in hours divided by 52 multiplied by 37 weeks left in the year. When I compared my calculation against an online calculator it came up with a slightly different answer. I am guessing it must be to do with averaging the 22.5 hours over 3 days.