C#正则表达式验证是否日期

    public static bool IsDate(string strDate)
    ...{
        if (string.IsNullOrEmpty(strDate))
            return false;
        string s_reg = @"^(?ni:(?=\d)((?'year'((1[6-9])|([2-9]\d))\d\d)(?'sep'[/.-])(?'month'0?[1-9]|1[012])\2

(?'day'((?<!(\2((0?[2469])|11)\2))31)|(?<!\2(0?2)\2)(29|30)|((?<=((1[6-9]|[2-9]\d)(0[48]|

[2468][048]|[13579][26])|(16|[2468][048]|[3579][26])00)\2\3\2)29)|((0?[1-9])|(1\d)|(2[0-

8])))(?:(?=\x20\d)\x20|$))?((?<time>((0?[1-9]|1[012])(:[0-5]?\d){0,2}(\x20[AP]M))|([01]?

\d|2[0-3])(:[0-5]?\\d){1,2}))?)$";
        Regex reg = new Regex(s_reg);
        if (reg.IsMatch(strDate.ToLower()))
              return true;
        else
              return false;
     }