I saw a question in the newsgroups today where a guy was asking
how he could get more than 10,000 hours in a cell, adding a hour number larger
that 10,000 to another time number the
formula did not give a correct answer.
Some of the answers suggested that Excel cannot hold a value
of 10,000 or more hours. This is actually incorrect. It is true that it is only
possible to enter a single value of 9,999:59:59 into a cell, but it can be
tricked into holding more.
For example, enter 5000:00 in cell A1 and the same in B1,
and a formula of =A1+B1 in another cell will show 10000:00.
It is even possible to enter it in a cell using a formula
and we get an answer of 11554:00.
Of course, the cell does have to be entered as [h]:mm to
see the result as more than 24 hours.