I am working a payroll calendar. I need a formula for determining the payroll period. We are paid (bi-weekly). So for illustrative purposes, I have the following:

Cell A1: Start Date
Cell A2: End Date
Cell A3: Payroll Period (help)

We have 26 payroll periods annually. Our Fiscal Year of 2015 started today (10-1-14). Here are actual dates for 2 payroll periods.....
Payroll Period 19 - 9/21/14 thru 10/04/14
Payroll Period 20 - 10/5/14 thru 10/18/14

Will certainly appreciate the help, Thanks!