Subtract month from a date

[mils]

Hi everyone!

I have the following variables:

DOE              Month
22/07/2013 6
24/08/2013 3
24/05/2013 4
10/09/2013 2
10/06/2013 3
13/02/2013 1
13/02/2013 5
15/12/2013 7
19/02/2013 14
19/11/2013 10

and I would like to know if it's possible to subtract the month from the DOE. I would like to get the following format:

DOE_subtracted
22/01/2013
24/05/2013
24/01/2013
10/07/2013
10/03/2013
13/01/2013
13/09/2012
15/05/2013
19/12/2011
19/01/2013

Please, let me know if anything is unclear.

Thanks in advance.

[David Marso]

See XDATE. and DATE. functions in the Syntax Reference.

mils wrote

Hi everyone!

I have the following variables:

DOE              Month
22/07/2013 6
24/08/2013 3
24/05/2013 4
10/09/2013 2
10/06/2013 3
13/02/2013 1
13/02/2013 5
15/12/2013 7
19/02/2013 14
19/11/2013 10

and I would like to know if it's possible to subtract the month from the DOE. I would like to get the following format:

DOE_subtracted
22/01/2013
24/05/2013
24/01/2013
10/07/2013
10/03/2013
13/01/2013
13/09/2012
15/05/2013
19/12/2011
19/01/2013

Please, let me know if anything is unclear.

Thanks in advance.

[David Marso]

NUMERIC newdate(EDATE).
COMPUTE #newmo=XDATE.MONTH(DOE)- MOD(Month,12) .
COMPUTE newdate   =DATE.MDY(#newmo+(#newmo LE 0)*12,
               XDATE.MDAY(DOE),
               XDATE.YEAR(DOE) - TRUNC(Month/12)-(#newmo LE 0)).

[Richard Ristow]

mils wrote (though it doesn't see to have gone out to the list),

>I have the following variables:
>
>DOE           Month
>22/07/2013      6
>24/08/2013      3
>24/05/2013      4
>10/09/2013      2
>10/06/2013      3
>13/02/2013      1
>13/02/2013      5
>15/12/2013      7
>19/02/2013      14
>19/11/2013      10
>
>and I would like to know if it's possible to subtract the month from the DOE.

First of all, you want your dates to be SPSS date values, and they
aren't -- there's no format that will display SPSS dates as
dd/mm/yyyy. Format EDATE will display them as dd.mm.yyyy, so I'm
reading your values into SPSS date values using that format. Your
input values, read as EDATE and printed with LIST, look like this:
|-----------------------------|---------------------------|
|Output Created               |24-JUN-2014 16:05:42       |
|-----------------------------|---------------------------|
        DOE Month

22.07.2013    6
24.08.2013    3
24.05.2013    4
10.09.2013    2
10.06.2013    3
13.02.2013    1
13.02.2013    5
15.12.2013    7
19.02.2013   14
19.11.2013   10

Number of cases read:  10    Number of cases listed:  10

David Marso suggested you look at XDATE. and DATE. functions. You
should, indeed, know these, but for your problem the DATESUMM
function is probably easier. Like this:


NUMERIC DOEminus (EDATE10).
COMPUTE DOEminus=DATESUMM(DOE,-Month,"Month").

LIST.

List
|-----------------------------|---------------------------|
|Output Created               |24-JUN-2014 16:05:42       |
|-----------------------------|---------------------------|

        DOE Month   DOEminus

22.07.2013    6  22.01.2013
24.08.2013    3  24.05.2013
24.05.2013    4  24.01.2013
10.09.2013    2  10.07.2013
10.06.2013    3  10.03.2013
13.02.2013    1  13.01.2013
13.02.2013    5  13.09.2012
15.12.2013    7  15.05.2013
19.02.2013   14  19.12.2011
19.11.2013   10  19.01.2013

Number of cases read:  10    Number of cases listed:  10

================================
APPENDIX: Test data and all code
================================
DATA LIST LIST/
    DOE        Month
    (EDATE10,      F3).
BEGIN DATA
    22/07/2013   6
    24/08/2013   3
    24/05/2013   4
    10/09/2013   2
    10/06/2013   3
    13/02/2013   1
    13/02/2013   5
    15/12/2013   7
    19/02/2013   14
    19/11/2013   10
END DATA.
LIST.

NUMERIC DOEminus (EDATE10).
COMPUTE DOEminus=DATESUMM(DOE,-Month,"Month").

LIST.

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[Jignesh Sutar]

I did a search for "DATESUMM" in the CSR and got zero hits?? Neither nothing on good ol' Google?

Is there any documentation for this mysterious function? And how it differs from DATESUM (if any)?

[David Marso]

I couldn't find DateSummationSensation anywhere either ;-)
I think Richard may have fat fingered the post.
-----------------
data list / d (ADATE).
begin data
10/12/2000
end data.
compute dd=DateSummationSensation(d,-1,'month').
FORMATS dd (adate).
list.

Jignesh Sutar wrote

I did a search for "DATESUMM" in the CSR and got zero hits?? Neither nothing on good ol' Google?

Is there any documentation for this mysterious function? And how it differs from DATESUM (if any)?

[PRogman]

Missed that too. It's not recognized in autocompletion nor in syntax highlight.
Interestingly it works with

COMPUTE DOEminus = DATES(DOE, -Month, "Month"). 

Probably minimum characters needed to find function...
 
/PR