Day: June 6, 2018

How Can I Subract DateTime Values?

June 6, 2018 admin No Comments สู่เส้นทางดิจิตอล

VFP supports arithmetic on datetime values. When you substract one datetime from another you get the elapsed time in SECONDS.

ie:

datetime(2008,1,1,15,0,0) – datetime(2008,1,1,14,0,0) is 3600 SECONDS.

However be carefull with datetime arithmetic and round the value to 0:

Code Snippet

lnSeconds = round(m.ltEnd – m.ltStart, 0)

And here is a little trick for formatting the result as time (in 24hr range):

Code Snippet

? TRANSFORM(RIGHT(TTOC(CTOT(‘0′)+(m.ltEnd – m.ltStart),1),6),’@R 99:99:99’)