Subtracting 2 dates but check cells if blank

[raburger]

Hi,

I need help. I want to subtract 2 columns from each other (Dates) but the cells need to be checked fist if blank and if blank it should ignore the one or use Today() in the other.

Example below. Row 4 and 5 work but row 6 gives me a 43027 value that should be a blank as I get the average delay in T so a 0 cant be entered if both cells are empty.

[TABLE="width: 500"]
<tbody>[TR]
[TD][/TD]
[TD]N[/TD]
[TD]O[/TD]
[TD]P[/TD]
[TD]Q[/TD]
[TD]R[/TD]
[TD]S[/TD]
[TD]T[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]Rev[/TD]
[TD]Sub Date[/TD]
[TD]App[/TD]
[TD]APP Wc[/TD]
[TD]Rej[/TD]
[TD]Resp Date[/TD]
[TD]Review Delay
[/TD]
[/TR]
[TR]
[TD]4[/TD]
[TD]a[/TD]
[TD]20/01/2017[/TD]
[TD]1[/TD]
[TD][/TD]
[TD][/TD]
[TD]28/01/2017[/TD]
[TD]=IF(T4="",TODAY()-O4,T4-O4)[/TD]
[/TR]
[TR]
[TD]5[/TD]
[TD]a[/TD]
[TD]23/01/2017[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]=IF(T5="",TODAY()-O5,T5-O5)[/TD]
[/TR]
[TR]
[TD]6[/TD]
[TD]a[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]
[/TD]
[TD]=IF(T6="",TODAY()-O6,T6-O6)[/TD]
[/TR]
</tbody>[/TABLE]

 

[steve the fish]

Maybe this if im reading correctly:

=IF(O4="","",IF(S4="",TODAY(),S4)-O4)

 

[raburger]

Maybe this if im reading correctly:

=IF(O4="","",IF(S4="",TODAY(),S4)-O4)

Thank you for the reply but it is not working. It leave the calculation cell blank when both cells are Blank(correct) but it doesn't calculate if one cell have a date in. So it must give a count with "today()" if one date is not completed but blank if both are blank.

Background:

This is for document control. We receive a document(first date) and then respond(second date). this is done on numerous revisions and we track both review time(Owner) and revision time(Contractor).

 

[steve the fish]

It will leave a blank if both cells are blank. It will use today if the cell in S is blank. By what you are saying it cant be possible for O to be blank but S to have a date present. So in what way doesnt it work?

 

[raburger]

It will leave a blank if both cells are blank. It will use today if the cell in S is blank. By what you are saying it cant be possible for O to be blank but S to have a date present. So in what way doesnt it work?

O will have a date before S. This if both cells are blank T must be blank but if O have a date and S not it must use Today() to calculate the delay.