Custom Data Validation Formula not working

[laxminarayana]

I am trying to restrict certain dates in a cell using the following custom Data validation formula

if(H2=12/10/2013,12/25/2013,False)

But unable to achieve the desired result. i am sure there is a problem in formula. Can some one please correct the formula.

 

[laxminarayana]

If you have a list of dates, enter them in a range and then use:
=ISNA(MATCH(H2,your_date_cells,0))

Thank You very much Rory.

 

[laxminarayana]

If you have a list of dates, enter them in a range and then use:
=ISNA(MATCH(H2,your_date_cells,0))

when i use the following formula

=ISNA(MATCH(H7,SHEET2!B2:B16,0))

excel is showing the following message box.
"You cannot use references to other worksheets or workbooks for Data Validation"

So it is not possible to give a range from other sheets?

PS: i am using excel 2007

Thank you

 

[RoryA]

Name the other range using Name Manager (on the Formulas tab) and then use the name in the validation formula.