Formatting results of time calculation?

[Guest]

I'm trying to calculate elapsed time spent on a task. In a task view, I
created two custom fields: "start time" and "end time"

I also created a formula called "elasped time" which is:
[end time] - [start time]

But the results of this formula are displayed as a serial number. Is there
any way to convert this to hh:mm? In Excel you can do this by applying
formatting to the cell with this formula. But the Outlook format columns
dialog box doesn't show a format field for formulas.

don't allow you to specify a format for a formula.

Outlook's help doesn't seem to even mention formulas - it's as if they don't
exist in the doc team's mind....

 

[Guest]

answering my own question:

The "Format" function (which I couldn't find documented anywhere) does what
I'm looking for:

Format([End Time]-[Start Time],"hh:mm:ss")