using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?<!\d)
(?:
[0-9]{4}
(?:
(?:0[1-9]|1[0-2]) (?:0[1-9]|1[0-9]|2[0-8])
|(?:0[13-9]|1[0-2]) (?:29|30)
|(?:0[13578]|1[02]) (?:31)
)
|
(?:
[0-9]{2}
(?:
0[48]
|[2468][048]
|[13579][26]
)
|(?:
0[48]
|[2468][048]
|[13579][26]
)00
)
02 (?:29)
)
(?!\d)
";
string input = @"aaa_20150229_bbb
aaa_2012-02-29_bbb
aaa_2000-02-29_bbb
aaa_20000229_bbb
20000228
2000-2-28
19120229
19000229
1696-2-29
16960229
20190228
aaa_1904229_bbb
aaa_18000229_bbb
aaa_17000229_bbb
aaa_16000229_bbb
2019-3-30
19960229
2019-02-28
20190228
20190229
aaa_20150130_bbb
aaa_20150131_bbb
aaa_2015-04-30_bbb
aaa_20150430_bbb
20190228
20190229
20200229
20000229
2000-02-29
2000-02-28
201911";
RegexOptions options = RegexOptions.IgnorePatternWhitespace;
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