timestamp grouped as time interval

[buattis]

hi everyone,

I've got a lot of table of recorded phone calls.

PHONE CALLS(callid, time, purpose)

and i want to create a query to count these calls grouped by half hour
interval like:

Time Period Total Calls
------------------ -----------------
9:00-9:30 25
9:30-10:00 40
10:00-10:30 55

is there a way to do this?

--Stefano

 

[Duane Hookom]

You can find the int of the time * 48 since there are 48 half hours in a day.
Then divide by 48.
Format(Int([TimeField]*48)/48,"Short Time")