using System.Text.RegularExpressions;
public static void Main()
string data = "2017-02-15T00:00:02+01:00";
string regex = @"(\d+\-\d+\-\d+)\w{1}(\d+\:\d+\:\d+)";
var matches = Regex.Matches(data, regex, RegexOptions.Multiline);
foreach(Match item in matches)
Console.WriteLine("field 1: " + item.Groups[1]);
Console.WriteLine("field 2: " + item.Groups[2]);