Normally Excel will use it's starting reference point to format a number into a time. This can be very confusing.

To get around this apply the edit code 00\:00\:00 to the number so for instance 234530 appears as 23:45:30 and Excel does not use it processes to convert the number to dates and times. 

Article ID: 16, Created On: 11/7/2012, Modified: 11/7/2012