请问验证 YYYY-MM-DD 的正则表达式怎么写？

Question

请问验证 YYYY-MM-DD 的正则表达式怎么写？谢谢！在CSDN上看到一个能验证三种格式的,可是我不会从里面挖出来这一部分,请教.if(Regex.IsMatch(start.Text,@"^(?:(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00)))(\/|-|\.)(?:0?2\1(?:29))$)|(?:(?:1[6-9]|[2-9]\d)?\d{2})(\/|-|\.)(?:(?:(?:0?[13578]|1[02])\2(?:31))|(?:(?:0?[1,3-9]|1[0-2])\2(29|30))|(?:(?:0?[1-9])|(?:1[0-2]))\2(?:0?[1-9]|1\d|2[0-8]))$"))
{
    errorProvider1.SetError(start,"日期格式必须为0000/00/00和0000-00-00和0000.00.00这三种格式");
    start.SelectAll();
    start.Focus();
}

Answer 1

"^(?:(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00)))(-)(?:0?2\1(?:29))$)|(?:(?:1[6-9]|[2-9]\d)?\d{2})(-)(?:(?:(?:0?[13578]|1[02])\2(?:31))|(?:(?:0?[1,3-9]|1[0-2])\2(29|30))|(?:(?:0?[1-9])|(?:1[0-2]))\2(?:0?[1-9]|1\d|2[0-8]))$"

Answer 2

^((((1[6-9]|[2-9]\d)\d{2})-(0?[13578]|1[02])-(0?[1-9]|[12]\d|3[01]))|(((1[6-9]|[2-9]\d)\d{2})-(0?[13456789]|1[012])-(0?[1-9]|[12]\d|30))|(((1[6-9]|[2-9]\d)\d{2})-0?2-(0?[1-9]|1\d|2[0-8]))|(((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))-0?2-29-))$

Answer 3

^((((1[6-9]|[2-9]\d)\d{2})-(0?[13578]|1[02])-(0?[1-9]|[12]\d|3[01]))|(((1[6-9]|[2-9]\d)\d{2})-(0?[13456789]|1[012])-(0?[1-9]|[12]\d|30))|(((1[6-9]|[2-9]\d)\d{2})-0?2-(0?[1-9]|1\d|2[0-8]))|(((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))-0?2-29-))$这个正则太 BT 了，眼睛花了，呵呵.......