I need to create a set of records for each client based on their payroll frequency. I need a payroll date for one client that has a weekly check date of Friday; another that has a b-weekly check date of Friday; another that has semi-monthly check dates on the 15th and last day of the month; etc. I need to create a check date schedule for the whole year for each client. I am told the best way is through a Loop expression, but I have limited experience in doing that. Any help is greatly appreciated

Basically you'll use two loops: one to move through the clients you need to create schedules for, and a second loop that makes all the schedule records for each client. Probably something like this (runs from the client's table):

Loop
Set Variable $Date: Get ( CurrentDate )
Loop
Set Variable $Date: $Date + 7
< Make schedule record for $Date >
Exit loop if $Date > Date ( 12 ; 31 ; year ( Get ( CurrentDate ) ) )
End Loop
Go to Record Request [ Next ; Exit After Last ]
End Loop

I'm not sure how you're making your schedule records, but that is the gist of it. The example above sets $Date to every 7 days for the rest of the current year; you'd need to come up with some other calcs to do things like "first monday of the month", "every two weeks on Monday", etc.

Our Pro Calendar has a repeating events script that does a lot of this and which might be a good place to look for examples on how to get the date math right.

Hope that helps.