ProAdmin has six (6) different methods for the calculation of elapsed time. There are two for Date Subtraction and two for Calendar Days, and one each for Business Days, and 360 days per year (30 per month). ProAdmin does not include the stop date when developing differences. The details of how those calculations are processed are shown below.

 

Date Subtraction

The date subtraction method calculates elapsed time in the following way by subtracting the start year from the end year, subtracting the start month from the end month and divides the result by 12, and finally subtracting the start day from the end day and dividing the result by either 365.25 or 360. When dividing by 360 ProAdmin assumes the end of month dates are on the 30^th. These three pieces are then added together to give you the service accrual. For example, if the start date for the service calculation is 09/25/1985 and the end date is 07/31/2004 ProAdmin would calculate service as

 

365.25		360
2004 – 1985 = 19 (7 – 9) / 12 = - 0.166667 (31 – 25) /365.25 = 0.0164271  19 - 0.166667 + 0.0164271 = 18.849760		2004 – 1985 = 19 (7 – 9) / 12 = - 0.166667 (30 – 25) /360 = 0.0136893 .013889 19 + - 0.166667 + 0.0136893 = 18.847222

 

 

Calendar Days

The calendar days method provides more precise results as it determines service as a ratio of how many days the member was eligible for service during the measurement period over how many calendar days there were during the measurement period. The denominator of the ratio can be true calendar days: 365 or366 or it can always use 365 days. For example, if the start date for the service calculation is 1/1/2012, the end date is 12/31/2012, and the measurement period is calendar year ProAdmin would calculate service as

 

True days		365
There are 366 days in the calendar year 2012 366/366 = 1		There are 366 days in the calendar year 2012 366/365 = 1.002740

 

Business Days

The business days method determines service as a ratio of the number of Mondays through Fridays during the measurement period that the member was eligible for service over the actual number of Mondays through Fridays during the measurement period. For example, if the start date for the service calculation is 09/25/1985, the end date is 06/30/2004, and the measurement period is calendar year ProAdmin would calculate service as

18 full measurement periods for 1986 through 2003

71 / 262 = 0.2709924 (for 1985)

130 / 262 = 0.4961832 (for 2004)

18 + 0.2709924 + 0.4961832 = 18.76717

 

360 days per year (30 per month)

360 days per year (30 per month) choice is the number of days between two dates divided by 360. This method determines days based on a 360-day year made up of twelve 30-day months. For example, if the start date for the service calculation is 09/25/1985, the end date is 06/30/2004, and the measurement period is calendar year ProAdmin would calculate service as

6 days for September of 1985

6,720 days for each full month from October of 1985 through May of 2004 crediting 30 days for each month

29 days for June of 2004

6 + 6,720 + 29 = 6,755 days

6,755 / 360 = 18.76389