SPSS Formats

SPSS supports numeric variables and strings, with conversion options and some automatic conversion functionality. There are several formats on top of numerics that impact visualization, not storage.

Datetime

A warning about data input

SPSS tries to be clever about reading data.

Under the format TIME, all of these are read in as "01:02", even though the format is a minimum of 5-wide:

• "1:2"

• "01 2"

• "01:02"

Under the format DATE, all of these are read in as "28-OCT-90":

• "28-OCT-90"

• "28/10/1990"

• "28.OCT.90"

• "28 October, 1990"

Datetime formats

Parse Timestamps

A macro for timestamp conversion, from dd/mm/yyyy hh:mm to SPSS DATETIME20:

define !str2datetime (in=!tokens(1) / out=!cmdend)
  numeric !out (DATETIME20).
  compute !out =
   date.mdy(
    number(char.substr(!in,1,2), f2),
    number(char.substr(!in,4,2), f2),
    number(char.substr(!in,7,4), f4)
   )
   + time.hms(
    number(char.substr(!in,12,2), f2),
    number(char.substr(!in,15,2), f2),
    0
   )
  .
!enddefine.

!str2datetime in=mytimestampvar out=mydatetimevar.

Create Timestamps

This is unfortunately long-winded.

data list free / a.
begin data.
1
end data.
dataset name TIMESTAMP.
execute.

string tmp_date (A11) datetime (A20).
compute tmp_date = $date.
alter type tmp_date (date11).
compute tmp_time = $time.

* Built-in formats.
compute datetime=string(tmp_date, ADATE10).
execute.

* Manual formats.
compute datetime=concat(
  char.substr(string(xdate.year(tmp_date),N4),3,2),
  string(xdate.month(tmp_date),N2),
  string(xdate.mday(tmp_date),N2),
  "_",
  string(xdate.hour(tmp_time),N2),
  string(xdate.minute(tmp_time),N2),
).
execute.

do if $casenum=1.
  write outfile 'timestamp.sps' /1 "define !timestamp() " datetime " !enddefine.".
end if.
dataset close TIMESTAMP.
execute.

insert file='timestamp.sps'.
execute.

Numerics

Formats only truncate the displayed value, or the value translated into data files. SPSS always retains data to original precision.

Given 123.45...

Strings

String variables are only formatted to a length. The format is specified as AN where N is the width.

CategoryRicottone