Time Check Function?

I am a database newbie so sometimes I am not sure if the problems I run into are my own ignorance or due to program limitations. Currently I use this formula to flag negative hours or long shifts for date/time start and stop times entered through a form:

IF(OR({Total Hours}<=0,{Total Hours}>12),“:question:”, " ")

I would also like to flag if someone enters a time that would be highly unlikely (after 8PM or before 5AM). Any suggestions for how to set up this function alone or with the current function would be appreciated! Or let me know if it’s impossible in AT. Thanks!