Calculate Start and End Time Stored as HH:MM when Shift extend past 00:00 (midnight)?

Hi all,

I hope you can help me.

I have a simple calculation error due to, what I believe, is a format issue.

Detail:

i have two fields used for capturing a start and end time - txtWorkShiftStart and txtWorkShiftEnd. The format of these two fields are HH:MM. To calculate the total shift time, one would subtract the two values (End - Start).

Here is the code i use for the calculation:

ws.Cells(rowToEdit, 138).Value = Format(CDate(Me.txtWorkShiftEnd.Value) - CDate(Me.txtWorkShiftStart.Value), "HH:MM")

This seems to work fine, until you have a shift starting before 00:00 (midnight) and end after 00:00 (midnight).

Example:

04:00 - 20:00 = 16:00 WRONG REMEMBER: it is a shift that started at 20:00 and ended 04:00 the next morning

It should be :

04:00 - 20:00 = 08:00 CORRECT REMEMBER: it is a shift that started at 20:00 and ended 04:00 the next morning

i thank you in advance!