Compute Months between dates

[Terry Pickering]

Thanks much to my "distant relative" John for pointing me in the right 
direction. Here is the code to compute the age at retirement. The next step 
is to compute the number of months to age 65. Thanks again John.

; compute age at retirement
define d-start-date date = &
    parm prompt "Date of Birth (mmddyyyy) " format mmddyyyy
define d-end-date date = &
    parm prompt "Date of retirement (mmddyyyy) " format mmddyyyy

define d-start-yyyy int*4 = floor(d-start-date / 10000)
define d-end-yyyy int*4 = floor(d-end-date / 10000)

define d-start-mm int*2 = floor(mod(d-start-date,10000) / 100)
define d-end-mm int*2 = floor(mod(d-end-date,10000) / 100)

;Calculate the number of whole years:

define d-whole-years = d-end-yyyy - d-start-yyyy - 1

define d-whole-months = (12 - d-start-mm) + d-end-mm - 1

;Now add up the months:

define d-total-months int*5 = (d-whole-years * 12) + d-whole-months

;Now figure out the years and months
define t-years int*5 = floor((d-total-months/12))
define t-months int*5 = mod(d-total-months,12)

report &
   tab 1 "Age at retirement:" &
   tab 20 t-years pic "^^" &
   tab 23 "years and" &
   tab 33 t-months pic "^^" &
   tab 36 "months" &
skip


set nohead

____________________________
Terry Pickering