A bi monthly pay frequency means there are 24 pay periods a year - two a month.
Ideally, these should be the same dates every month but it can be confusing when
one of the pay dates falls close to the end of the month, particularly in
Ace Payroll uses the following logic when calculating bi monthly pay dates
If a pay date falls on the 15th of the month, it is assumed the next pay date
falls at the end of the month.
If a pay date falls on the last day of the month, it is assumed the next pay date
is the 15th of the following month.
If a pay date falls prior to the 15th of the month, it is assumed the next pay
date is 15 days after that, unless that date is the end of the month in which
case the pay date is the day before the end of the month. In other words, if a
pay date is 14th February in a non leap year, the next pay date is 27th February.
If a pay date falls between the 16th and the day before the number of days in the
month, the next pay date is that day value less 15 of the following month, with
the maximum date being the 14th of the following month.
It will be seen from the following source code that a very slight "creepage" can
result from bi monthly pays not set to the 15th or last day of the month.
For exact calculation, set the pay date to either the 15th or last day of the
month, and the results are guaranteed to be accurate.
Otherwise it is a good idea to verify the pay date is what you expect each pay