data validation

[prakashkumar]

first 2 digit must be numerical value
third digit must be "/"
4th and 5th digit must be numerical value
6th digit must be "/"
7 8 9 10 digit must be numerical value
else say some error message

 

[etaf]

how about
=AND(ISNUMBER(LEFT(a1,2)*1),ISNUMBER(RIGHT(a1,4)*1),ISNUMBER(MID(a1,4,2)*1),MID(a1,3,1)="/",MID(a1,6,1)="/")
in datavalidation

maybe a simplier formula - say removed the / , check there are 2 and the rest is a number

 

[Fluff]

Duplicate to: how to allow only specific date format in a cell of excel

In future, please do not post the same question multiple times. Per Forum Rules (#12), posts of a duplicate nature will be locked or deleted.

In relation to your question here, I have closed this thread so please continue in the linked thread.