Gentlemen
The thing to appreciate here is the way Excel treats time. As far as it is concerned, time is a number. One day corresponds to the number one, 12 days to the number twelve, 12 hours is 0.5, and 1 minute is 0.00069444444444444400.
When you add up hours and minutes and the total is greater than 24 hours it will be displayed as just the hours over the whole days. The way to add totals of hours is to allow excel to treat them as numbers and use the sum function to add them into the total.
If you have a series of hours and minutes which add up to say 34 hours 15 minutes, this will display as 10:15 if the cell is formatted HH:MM or as 1.42708333333 etc. etc if it is formatted to display as a number. ie 1.42708333333 days
To display this number as hours and minutes:
Take another cell and enter the formula
"INT(CELL*24)" where CELL is the cell number with the sum of time.
This will display the whole hours.
In an adjacent cell enter the formula
"60*((D5*24)-INT(D5*24))"
This will display the number of minutes.
To display hours and minutes in one cell, use the concatenate function...thus
"CONCATENATE(HOUR CELL,":",MINUTE CELL)
And voila, your total hours and minutes.
This is a bit clumsy and could probably be streamlined if I could be ars*d, but it works and if you hide the intermediate cells then they will be....well....hidden
