You will have to come up with something yourself...I can't think of any predefined functions that will help.
You will need to check if the start time is between a certain range.... Format([StartTime], "hh") Between 7 And 3
and then do the same for the end time maybe...if that matters.
My only comment is how do you plan to handle crossovers or an time that is "just" outside your ranges...
So if the start time is 6:49 and end time is 3:07, does that qualify as first shift, or second, or whatever???
I would suggest just supplying a choice of shifts and letting the users select that as well, if this an item that needs to be captured. Otherwise, I think you will have some difficulty coming to a solution that will ALWAYS find the appropriate shift based on your criteria.
But feel free to repost specific questions and maybe some sample code, data, and expected results and I will be glad to try to help work something out as close as possible.
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People think it must be fun to be a super genius, but they don't realize how hard it is to put up with all the idiots in the world. (Calvin from Calvin And Hobbs)
Robert L. Johnson III
CCNA, CCDA, MCSA, CNA, Net+, A+, CHDP
VB/Access Programmer