Math with time durations (not time of day) in excel

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

JJohn@officeformac.com - 28 Aug 2008 03:44 GMT

Version: v.X
Operating System: Mac OS X 10.4 (Tiger)
Processor: Power PC

Does anyone know how to easily do simple math with times? Let me explain: if I use the standard hh:mm format to indicate a task time duration, Excel thinks this is a time-of-day and 30:15 becomes 6:15 am. I want it to be used as 30 hours and 15 minutes. I want to add task times, subtract them from each other and do simple ratios and graphing.

This should be easy. Yes, I have created functions that parse the time strings and convert them to total seconds and then do the math in seconds and re-generate the text strings to show the results but this is tedious and sometimes results in weird errors. Any ideas would be greatly appreciated?

Reply to this Message

CyberTaz - 28 Aug 2008 15:53 GMT

The values you're working with aren't Times, they're quantities or amounts
of time :-) The simplest solution is to *not* format the amounts as Times in
the first place - enter them as fractional values. Using your example, 30
hrs & 15 min would be 30.25, the cell being formatted for General or Number
rather than Time.

If the periods are being derived by subtracting a starting time from an
ending time build the conversion to fractional values into that calculation.

HTH |:>)
Bob Jones
[MVP] Office:Mac

On 8/27/08 10:44 PM, in article 59b580ee.-1@webcrossing.caR9absDaxw,

> Version: v.X
> Operating System: Mac OS X 10.4 (Tiger)
[quoted text clipped - 10 lines]
> re-generate the text strings to show the results but this is tedious and
> sometimes results in weird errors. Any ideas would be greatly appreciated?

Reply to this Message

Mac Forum / Applications / Excel / August 2008

Math with time durations (not time of day) in excel