cant get cells to stay blank when no date is entered in other cells

[steve400243]

hello, I have a problem that i'm sure will be an easy fix but i am stumped and cannot get it to work right. The DELIVERED date is in column "O", the "LFD" column is "p". I want the LFD date to populate automatically once the delivered date is manually entered. the LFD date is the delivered date + 4 days. The problem I am having is that If there is no date in the delivered column i want the cell in column P to be blank. When i copy down the column i get the date reference of 1/4/1900? Thanks for all help.


[TABLE="width: 279"]
<colgroup><col><col></colgroup><tbody>[TR]
[TD]DELIVERED [/TD]
[TD]LFD [/TD]
[/TR]
[TR]
[TD]9/21/2017[/TD]
[TD]9/25/2017[/TD]
[/TR]
[TR]
[TD]9/22/2017[/TD]
[TD]9/26/2017[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]1/4/1900[/TD]
[/TR]
</tbody>[/TABLE]

 

[Tetra201]

... If there is no date in the delivered column i want the cell in column P to be blank...

Try

=IF(ISNUMBER(O2),O2+4,"")

 

[steve400243]

Try

=IF(ISNUMBER(O2),O2+4,"")

Excellent, thanks very much for your time. I appreciate it!