calculating Endtime-Starttime In Access

[norriz]

Guys,
I can really use some help.
table below:
StartDt EndDt Qty
3/2/16 10:21 AM 3/2/16 10:21 AM
I tried using formula below to get actual time:
IIf([Activity_HBC]![EndDt]-[Activity_HBC]![StartDt]<='0',0,[Activity_HBC]![EndDt]-[Activity_HBC]![StartDt])*24
The resulr results below is in negative:
StartDt EndDt Qty actual uniquekey
3/2/16 10:21 AM 3/2/16 10:21 AM 1 -0.00000000017 409026
How do i write my formula to show that if the results is zero or less, output zero.
Thanks

 

[Micron]

My guess is that your problem is that you are treating the first 0 as text and the next as a number: <='0',0
It cannot make this comparison without nesting other functions. Remove the single quotes and see what you get. Or are you trying to drop a zero into a text field on purpose?