Regular Expression for Date not working

[Akhila]

Hi,

Code:

([1-9]|1[012])[//]([1-9]|[12][0-9]|3[01])[//](200[0-9])

In the above expression Can we replace double slash [//] with single slash /

I wondering whether below expression is valid or not. If not why?

Code:

([1-9]|1[012])/([1-9]|[12][0-9]|3[01])/(200[0-9])

Thanks,
Akhila