DateTime formats used in InvariantCulture

Question

I have to pre-validate in Javascript a string that will be a DateTime in c#. The DateTime parse uses InvariantCulture.

Does anyone know the DateTime formats defined for InvariantCulture?

Phares

Answer 1

Compiling information from standard date and time format strings:

Pattern	Example
Short Date Pattern ("d")	MM/dd/yyyy
Long Date Pattern ("D")	dddd, dd MMMM yyyy
Full Date Short Time ("f")	dddd, dd MMMM yyyy HH:mm
Full Date Long Time ("F")	dddd, dd MMMM yyyy HH:mm:ss
General Date Short Time ("g")	MM/dd/yyyy HH:mm
General Date Long Time ("G")	MM/dd/yyyy HH:mm:ss
Month ("M", "m")	MMMM dd
Round-Trip ("O", "o")	yyyy-MM-ddTHH:mm:ss.fffffffK
RFC1123 ("R", "r")	ddd, dd MMM yyyy HH:mm:ss GMT
Sortable ("s")	yyyy-MM-ddTHH:mm:ss
Short Time ("t")	HH:mm
Long Time ("T")	HH:mm:ss
Universal Sortable ("u")	yyyy-MM-dd HH:mm:ssZ
Universal Full ("U")	dddd, dd MMMM yyyy HH:mm:ss
Year Month ("Y", "y")	yyyy MMMM

Catheryncatheter

Seeming as MM/dd/yyyy is used almost exclusively by Americans (en-US) but InvariantCulture is ostensibly meant to be universal, it would have been better if InvariantCulture used ISO 8601 (yyyy-MM-dd and HH:mm:ss) date and time formats instead of its current format. It means I can't use InvariantCulture for appropriate culture-neutral logging, for example. – Spoon

To expand on my comment above (from 3 years ago) I have posted copy-and-pastable code that gives you InvariantCultureWithIso8601 which is an immutable ISO 8601 CultureInfo instance, with some handy DateTime extension methods too. HTH. – Spoon

@Spoon if you know what you want (yyyy-MM-dd and HH:mm:ss), then you can specify that. InvariantCulture just make some guarantees, but it doesn't matter that much which ones are picked, as long as they never change. – Ondrea

Answer 2

It's very easy to test.

public static void Main()
{
    var d = DateTime.Now;

    Console.WriteLine("Date format (long):  {0}", d.ToString("D", CultureInfo.InvariantCulture));
    Console.WriteLine("Date format (short): {0}", d.ToString("d", CultureInfo.InvariantCulture));
    Console.WriteLine("Full format (long):  {0}", d.ToString("F", CultureInfo.InvariantCulture));
    Console.WriteLine("Full format (short): {0}", d.ToString("f", CultureInfo.InvariantCulture));
    Console.WriteLine("Time format (long):  {0}", d.ToString("T", CultureInfo.InvariantCulture));
    Console.WriteLine("Time format (short): {0}", d.ToString("t", CultureInfo.InvariantCulture));
    Console.WriteLine("General format (long):  {0}", d.ToString("G", CultureInfo.InvariantCulture));
    Console.WriteLine("General format (short): {0}", d.ToString("g", CultureInfo.InvariantCulture));
}

}

Output:

Date format (long):  Monday, 16 October 2017
Date format (short): 10/16/2017
Full format (long):  Monday, 16 October 2017 20:12:45
Full format (short): Monday, 16 October 2017 20:12
Time format (long):  20:12:45
Time format (short): 20:12
General format (long):  10/16/2017 20:12:45
General format (short): 10/16/2017 20:12

Code on DotNetFiddle.

Catalonia

Answer 3

Its more or less the same as en-us but uses as 24 hour time instead of 12 hour am/pm and fills in full MM/DD/YYYY.

var date1 = d.ToString(CultureInfo.InvariantCulture);   // "05/21/2014 22:09:28"
var date2 = d.ToString(new CultureInfo("en-US"));       // "5/21/2014 10:09:28 PM"

Mats

Answer 4

• "O" or "o": yyyy-MM-ddTHH:mm:ss.fffffffzz
• "R" or "r": ddd, dd MMM yyyy HH:mm:ss
• "s": yyyy-MM-ddTHH:mm:ss
• "u": yyyy-MM-dd HH:mm:ssZ

Sources [1]: https://learn.microsoft.com/en-us/dotnet/standard/base-types/standard-date-and-time-format-strings

Roofdeck