Dates and times

Formats

There are three common formats across SAS, SPSS and Stata.

Date (number of days)

SAS: MMDDYY, DDMMYY, YYMMDD, DATE
Spss: n/a
Stata: %td

Time (number of seconds):

SAS: TIME, HHMM, TOD
Spss: TIME, DTIME
Stata: n/a

DateTime (number of seconds):

SAS: DATETIME
Spss: DATE, ADATE, SDATE, DATETIME (as milliseconds)
Stata: %tc, %tC

Offsets

Dates and date times use a difference offset to R:

SAS: 1960-01-01 (3653 days)
Spss: 1582-10-14. (141428 days)
Stata: 1960-01-01. (3653 days)

References