how to set data validation on cell that display a date in Excel?

[SBA22000]

I have a cell where user should enter a date in the format "mm/dd/yy" so I
formated the cell to do so. when user enter a diffrent date format, the OS
convert it the predifined cell formating. but when an illogical entry is made
no thing happends. does data validation allow me to do so and dispaly a
warning message and how can I do so?

 

[Debra Dalgleish]

Data validation can't control the format in which a data is entered. It
could ensure that a date is within a specified range, or that a valid
date is entered.

What validation did you use?

 

[SBA22000]

Hi sorry for the delay I was in vacation. the company policy set the date
format to be mm/dd/yy. I applied cell formating to display the date format as
specified. I noticed that if user enter another DATE format, the OS convert
it automatically to display the cell formating. But, if user enter "anything"
different from a date format it will display the input as made even if it's
not a date. that's why I need a prompt to show and ask user to enter a
correct date format. I thought that I can accomplish this with data
validation. I'm not able to do so! is there a way to do it?
Thanks for the support.