This is a bit wierd. Parsing a text field with a valid timespan fails if I try to be precise!
const string tmp = \"17:23:24\"; //works var t1 = TimeSpan.Pars
Try this:
var t2 = TimeSpan.ParseExact(tmp, "c", System.Globalization.CultureInfo.InvariantCulture);
Source: Standard TimeSpan Format Strings