服务器端验证DateTime Stamp

In my application, server side date validations were done through IsDate which is very inconsistent in behavior. I used isValid("USdate",DateVar), that works fine with incoming dates, but when DateVar is a date time stamp it fails. Values coming in DateVar could be anything, a date, a time, a date & time or even some invalid data. If I use Date mask with isValid, that behaves like isDate and of no use. How I can accomplish this. In my application, server side date validations