using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(((\d{3}[1-9]|\d{2}[1-9]\d|\d[1-9]\d{2}|[1-9]\d{3})(\/)(((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))|((0[469]|11)(\/)(0[1-9]|[12]\d|30))|(02(\/)(0[1-9]|[1]\d|2[0-8]))))|(((\d{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))(\/)02(\/)29))$";
string input = @"2020/02/29
2021/02/29
2021/08/25";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx