I need to set up a column that displays calendar days so that the project team can see the overall duration in addition to the working days. When I use the DateDiff("d",[Start],[Finish]) formula it works, however any task line or space in he schedule shows #ERROR, Is there a formula that can be used to eliminate this error message? Thank you!
I don't know about 2010, but in 2013 it generally works well unless you have a task row that does not yet have valid start and end dates, in which case you get #ERROR.
In that case, I set the custom field type to "Text" and used the following formula:
IIf(isdate([Start]) And isdate([Finish]),datediff("d",[Start],[Finish]),"")
If you absolutely must have the field type as numeric then using:
IIf(isdate([Start]) And isdate([Finish]),datediff("d",[Start],[Finish]),0)
...will avoid the display of #ERROR but does mean that all task rows have a numeric value.