In my new position payroll accruals hadn't been made for a few months, so the owner can calculate bonuses for the managers of various locations, I caught them up using what I thought was standard method for determining the amounts. But it gets complicated.

I did the accruals based on unpaid days left in each month's open pay period, with 1 having more as the next payday was Aug 1 so we had a full unpaid pay period plus 4 days before payday on the 1st. That month also has 3 paydays. When I did the accruals last day of the previous month, then reversed them on the first, the month with 3 paydays (1st, 15th, 29th) still has higher wages expense than other months by 1 payroll. 

(they don't do PTO accruals and estimate the wages/commissions so it's not textbook)

The boss wants me to manipulate the numbers to even things out more, which I did but since each month's accrual affects the prior/next that gets to be a snowball. He IS trying to be fair and not have a spike for the month with 3 paydays.

He is basing one bonus calculation off wage expense (including benefits) as a percent of income-the lower the better but too low is a red flag. Previous bonuses, training compensation, etc are not excluded. Staff are paid mainly on flat rate or sales commissions with some getting a management salary as well. The higher the sales, the higher the wage expenses exponentially. 

There are a number of other variables that might skew the P&L for these numbers (for example an employee might move to another location mid pay period, or an error on benefits causing one payroll to appear inflated/deflated)

If one month has 3 paydays, why wouldn't the P&L reflect that? Accruals reflect the accrued pay owed at month's end, not a tool to make every month even steven, correct?

How carried away does one get with accruals for a privately held company? It seems like I could spend many hours estimating/calculating this in more detail for the 15 locations, only to reverse it a day later, doesn't this effort make more sense at year's end? 

I hope I explained this sensibly! Thank you!