Tracking Term-Time Only Employees on Advanced Payroll (stretch pay and annual leave)

Can I ask how I track the almost 30 employees that I have who work term-time only on Quickbooks Advanced Payroll? I run payroll for a pre-school where the school staff receive 38 weeks pay stretched over 52 weeks. This is so that they receive a regular monthly salary as opposed to being paid just for hours worked (i.e. nothing in August, for example). I have not yet found a way to track this as the issue I have is that their hourly rate falls below minimum wage as it is stretched over the year whereas in actual fact they are all at or above it. I keep getting warnings about this when I run payroll so short of turning this warning off (easy option) I would like to properly account for this as well as correctly accruing holiday. Thank you in advance.