Unless I am not understanding what it is you are asking the times will be
irrelevant, you only want to know how many midnights the person was in the
bed.

If the Date and time are in the same cell, (ie Admission Date & time in A1
and Discharge date and time in B1) then use:

=INT(B1)-INT(A1)-1

If the Date and time are in separate cells, (ie Admission Date in A1,
Admission time in B1 & Discharge Date & time in C1 & D1 respectively/ then
use:

=C1-A1-1

In both cases format as General or Number

--
HTH

Sandy
In Perth, the ancient capital of Scotland
and the crowning place of kings


Replace @mailinator.com with @tiscali.co.uk


"ICU research" <ICU wrote in message
...
I have two Dates and Times (Admission Date & Time) and Discharged Date &
Time). I need to calculate the number of bed nights (patient must be in
the
unit at 00:00:00