how to parse a string to DateTime in c#?

May 13, 2023

I want to subtract dt2 (2023-12-31) from dt1 (2023-01-01) in c#, but when i try to debug the codes it says " System.FormatException: ‘String ‘2023-12-31 08:00:00′ was not recognized as a valid DateTime.’ "

my codes:

DateTime dt1 = DateTime.Parse("2023-01-01 08:00:00");
DateTime dt2 = DateTime.Parse("2023-12-31 08:00:00");
TimeSpan diff = dt2.Subtract(dt1);
Console.WriteLine(diff.ToString());

How i can fix this error?

>Solution :

Your issue is not about subtracting DateTimes but the exception happens when you parse them. The reason is that DateTime.Parse uses your current culture’s information(like date-separator) when you don’t pass another. It seems that you are from iran, so this lets reproduce the exception:

System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("fa-IR");
DateTime dt2 = DateTime.Parse("2023-12-31 08:00:00");

So one way to fix it is to pass CultureInfo.InvariantCulture:

DateTime dt1 = DateTime.Parse("2023-01-01 08:00:00", CultureInfo.InvariantCulture);
DateTime dt2 = DateTime.Parse("2023-12-31 08:00:00", CultureInfo.InvariantCulture);