Time Averages/ Time of Day and Minutes

[Scotty]

I am working on a database that tracks dispatch time/ arrival time/ and how
many minutes to scene. How do I 1: record the time and then query the time to
show an average dispatch time? (I assume the arrival time equation will be
the same) 2: set up a query to calculate the difference in arrival time from
dispatch time, and then the subsequent average response time?

 

[John W. Vinson]

I am working on a database that tracks dispatch time/ arrival time/ and how
many minutes to scene. How do I 1: record the time and then query the time to
show an average dispatch time? (I assume the arrival time equation will be
the same) 2: set up a query to calculate the difference in arrival time from
dispatch time, and then the subsequent average response time?

The latter. Record the date and time of dispatch, and the date and time of
arrival in a Date/Time field (you want the date in case the call spans
midnight). Use the DateDiff() function to calculate the elaped time, and
average that.

Don't just subtract the dispatch time from the arrival time - that will return
a Date/Time value which will superfically look normal (0:26:30 for 26 minute
thirty second response time), but summing and averaging it may get you into
peculiar results. Date/Time values are best used for specific points in time,
not for durations.

John W. Vinson [MVP]