how to calculate total hours in infopath

Hi there, I have a start & end time field set as (time) data field in 24hours format.
What's the formula for the 3 field to calculate todays hours?
the formula i used:
(end time - start time) / ( 1/24)

...after publishing the form, the field on form is red indication NaN
any help is much appreciated!
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Clay FoxDirector of Business IntegrationCommented:
I do not think you would want the divide by 1/24th

endtime - starttime gets you the difference.

If you want to display the time in 24hour then the format properties of your control to that format.

You can also use a substring-after(time, "T") to get just the time of a datetime field and put it in an expression box or text field.

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digitaldarkhorseAuthor Commented:
digitaldarkhorseAuthor Commented:
digitaldarkhorseAuthor Commented:
This blog post includes step by step and codes to include in each respective field to calculate total hours. It's awesome!
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