Adding Time Values

[Caspar]

I want to add e.g. ten minutes to a list of time values - how do I do this??

[Ian]

I changed the value from (h):mm to (hh):mm but the sum still will not go past 24hrs it reverts back to 0?:?? after passing a 24hrs period, I am trying to count the number of hours worked in a week period in hr:min value.
Any ideas??

[Yvonne Wright]

I wanted to be able to add working hours, but found that it would not calculate over 24hrs correctly. Once I opened this page the answer was there straight away no faffing around excellent I am well chuffed

[Yvonne Wright]

I wanted to be able to add working hours, but found that it would not calculate over 24hrs correctly. Once I opened this page the answer was there straight away no faffing around excellent I am well chuffed

[ExcelTip]

Problem:

When using a standard SUM formula to add the time values in column B (=SUM(B2:B5)), a false result of 4:23 is returned, rather than the actual sum of 28:23.

Solution:

Excel\'s default time format does not allow a time value to exceed 24 hours. This is the cause of the above error.
To properly display a sum exceeding 24 hours, change the format of the cell from \"h:mm\" to \"[hh]:mm\".