Calculating Time between time stamps

[#1]

I've been trying to modify this statement in this post:

http://community.qlik.com/thread/79893

I'm dealing with pure time stamps, no dates, and I need to calculate the time between multiple time stamps.

I read somewhere there is a problem with using MM for minutes.

Can I modify this or other statements to calculate time:

=Ceil(Interval(Date#([Field2], 'MM/DD/YYYY hh:mm:ss TTT') - Date#([Field1], 'MM/DD/YYYY hh:mm:ss TTT'), 'DD' ))

or are there other options?

Thank you for your help!

[#2]

Yes, we do have some integrity issues, that I will have to tackle with case statements, but this was the biggest piece I needed to master.  Will try out your suggestions and appreciate you greatly for taking the time to help!

[#3]

Thanks Sean. Works great with the .csv data, but not the "real" data source.

I'm working with a Cache database - apparently dates are stored numerically and i know Qlikview doesn't always cooperate in the date arena.

Still searching for a functional expression to create a date/time stamp from separate date and time fields.

Help!

[#4]

Thank you!  The DTS are working great, as are the time diff calculations!

Now to build some time variables...

Appreciate all of you!!!!