string dt = \"10/25/2010 11:40:05 PM\";
var currentThread = Thread.CurrentThread.CurrentCulture; //ru-RU
DateTime dateTime = DateTime.Parse(dt); //Exception!
Use a custom Date and Time format string, using either ParseExact or TryParseExact.
DateTime dateTime;
DateTime.TryParseExact(
dt,
"MM/dd/yyyy hh:mm:ss tt",
CultureInfo.InvariantCulture,
DateTimeStyles.None,
out dateTime
);
The string cannot be parsed as a Russian DateTime representation since the Russian culture doesn't use AM/PM, hence the use of the use of CultureInfo.InvariantCulture which is a US like culture (it represents no specific culture, but is modeled after the en-US one).