Here i am providing some useful regular Expression which are acceptable by most of the web developers. I have found them in web.
Email Address validation
|Description:||Most email validation regexps are outdated and ignore the fact that domain names can contain any foreign character these days, as well as the fact that anything before @ is acceptable. The only roman alphabet restriction is in the TLD, which for a long time has been more than 2 or 3 chars (.museum, .aero, .info). The only dot restriction is that . cannot be placed directly after @. This pattern captures any valid, reallife email adress.|
Date and Time
|Description:||This regular expressions matches dates of the form XX/XX/YYYY where XX can be 1 or 2 digits long and YYYY is always 4 digits long.|
You can have more information about RegX in the following site: http://regexlib.com/DisplayPatterns.aspx?cattabindex=1&categoryId=2