holiday entitlement - school bus employment (No Contract)

Your annual leave entitlement is based on the hours for which you receive payment from your employer. All other time (e.g. unpaid leave and/or time on benefits) does not count for the purposes of calculating leave entitlement.
 
Can you explain this a bit better
Is it you are not available for "other work" and can only work 183 days driving the school bus
Or there is no work available to you from your employer other then the 183 days of driving the school bus

Also can you clarify what happens when the school closes for holidays, you sign on during the summer break but do you sign on for the other holidays like mid term and Christmas

My understanding of your situation is you work 183 days of the year for 5 hours a day which gives you an entitlement of 73 hours of paid leave
183 x 5 x 8%
But again it's my understanding that if he's paying you this holiday entitlement while he has no work for you that this still counts as accruing holiday entitlements so now the calculation is 183 x 5 + 73 x 8% = 79 hours of paid leave

From Citizens Information
When calculating your holiday entitlement, your employer should include all the hours you worked, including time spent on annual leave