Re: [patch #5637] Implement DATESUM, DATEDIFF expression function

[Daniel E WILLIAMS]

Ben,

 

The time of day appears to count for DATEDIFF.  The difference in years between 1 Jan 2004
at 2pm and 1 Jan 2005 at 1pm equals zero, while the difference in years between 1 Jan 2004
at 2pm and 1 Jan 2005 at 3pm equals one.

 

Time of day also appears to count for DATESUM.  1 Feb at 14:00, with one month added, becomes 1 Mar at 14:00.  The code I sent tries three different versions of DATESUM; the default, "rollover", and "closest" methods.  I cannot figure out what the difference between "rollover" and "closest", but I know that "closest" is the default.

 

You are right.  The SPSS documentation is not very clear on this issue.  I've attached code and an output file that shows the calculations I made.  Thanks.

 

Dan Williams
Forecasting, Research and Analysis Office
Department of Human Services
State of Oregon, USA
503 947 5354

date_stuff_for_SPSS.SPS
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date_stuff_for_SPSS.sav
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