Summing a list of time values

[bgcogen]

Hi.

I really need to add a list of time values in a query but I continually get all kinds of different error messages. What am I doing wrong??

I am able to subtract two values from each record in the query [Opening and closing time], I use the expression Closed_time: Format([Closing time]-[Opening time],"Short Time") and everything is grand. But then I need to sum all these values but I keep on getting errors like SQL and "you tried to execute a function which doesn't have the closed_time aggregate function.

Do you have any ideas????

Thanks a million.
Declan

 

[clive2002]

have you tried saving the query at the point when everthing is grand and using another query to sum the time values, or just summing the opening and closing time and then using your formula when already summed