Performing arithmetic with date fields

Suppose you had an input file with gregorian input dates in ccyymmdd form like this:

You can use these statements:

  OUTREC BUILD=(1,8,Y4T,ADDDAYS,+50,TOGREG=Y4T(/),2X,
      1,8,Y4T,SUBMONS,+7,TOGREG=Y4T(/),2X,
      1,8,Y4T,ADDYEARS,+2,TOGREG=Y4T(/))

to display the original date and perform arithmetic on these dates as follows:

Add 50 days
Subtract 7 months
Add 2 years

The results produced for this OUTREC statement are:

2007/04/24  2006/08/05  2009/03/05   
2008/02/01  2007/05/13  2009/12/13   
2008/04/09  2007/07/19  2010/02/19   
2008/10/21  2008/02/01  2010/09/01   
2010/01/11  2009/04/22  2011/11/22   
2009/03/06  2008/06/15  2011/01/15   
2010/11/04  2010/02/15  2012/09/15   
2010/08/19  2009/11/30  2012/06/30

You can perform various types of arithmetic on date fields in either julian or gregorian form, with 2-digit (Y2x) or 4-digit (Y4x) years, in CH, ZD or PD format. You can convert the result to the same form of date or another form, with or without separators.

You can use the following date arithmetic functions:

ADDDAYS, ADDMONS and ADDYEARS can be used to add days, months or years to a date field.
SUBDAYS, SUBMONS and SUBYEARS can be used to subtract days, months or years from a date field.
DATEDIFF can be used to calculate the number of days between two date fields.
NEXTDday can be used to calculate the next specified day of the week for a date field (where day can be SUN, MON, TUE, WED, THU, FRI or SAT).
PREVDday can be used to calculate the previous specified day of the week for a date field (where day can be SUN, MON, TUE, WED, THU, FRI or SAT).
LASTDAYW, LASTDAYM, LASTDAYQ and LASTDAYY can be used to calculate the last day of the week, month, quarter or year for a date field.

For complete details on using date field arithmetic functions, see z/OS DFSORT Application Programming Guide.