Is the time stored by itself or do you have the date and time?
Field: TimeOnly: TimeValue(Nz(YourDateField,#00:00:00#))
Criteria: Between #09:45:00 AM# and #10:30:59 AM#
If yourdatefield has no date component then you won't need the TimeValue
function or the NZ function. If your Date field is never null, then you
won't need the NZ function.