Check if a valid date?

[Guanjin Peter]

I'm currently using the below code to check if it's blank. Actually I wanted to check if it is a valid date. I can't really use:
=IF(B1=dd-mm-yyyy,TEXT(WEEKDAY(B1),"dddd"),"")
so any idea?

=IF(B1="","",TEXT(WEEKDAY(B1),"dddd"))

 

[Joe4]

Dates are actually stored as Numbers in Excel (specifically, the number of days since 1/1/1900). So you can use the ISNUMBER function, i.e.

=IF(ISNUMBER(B1),TEXT(WEEKDAY(B1),"dddd"),"")

 

[Guanjin Peter]

there wasn't a need to specifcy true or false...that's strange.....

well it works wonders! Thanks!

It'll work for Vb code too?

like:
If Range("b1").Value = "ISNUMBER(B1)"

 

[schielrn]

If it is a number it is presumed true and if it is not then it is presumed false.

In if statements =TRUE and =FALSE are not really needed., but you could put:

=IF(ISNUMBER(B1)=TRUE,TEXT(WEEKDAY(B1),"dddd"),"")

But it is redundant.

 

[Joe4]

It'll work for Vb code too?

like:
If Range("b1").Value = "ISNUMBER(B1)"

Actually, VBA has an ISDATE function that works even better, as it differentiates numbers from dates (presumably by how they are formatted).

So, in VBA, you can use:

 If IsDate(Range("B1")) Then
...

 

[Guanjin Peter]

wow thanks!