Question

An api im using is providing me a date. This date is of type string and is presented in the format:

Mon Nov 16 19:15:09 +0000 2009

DateTime.TryParse() fails when this value is provided. Can anyone point me in the right direction?

Answer 1

Using the DateTimeOffset class in order to handle the offset.

[TestMethod]
public void test()
{
  string s = "Mon Nov 16 19:15:09 +0000 2009";

  var result = DateTimeOffset.ParseExact(
    s, 
    "ddd MMM dd HH:mm:ss zzz yyyy", 
    System.Globalization.CultureInfo.InvariantCulture);

  Assert.AreEqual(16, result.Day);
  Assert.AreEqual(11, result.Month);
  Assert.AreEqual(2009, result.Year);
  Assert.AreEqual(19, result.Hour);
  Assert.AreEqual(15, result.Minute);
  Assert.AreEqual(9, result.Second);
  Assert.AreEqual(0, result.Offset.Hours);    
}

Change the offset in the string – e.g. ‘0600’ and then change the offset assertion to match, it’ll work.

You can then convert this into a DateTime if you have to – but you lose the offset information; so you have to decide whether you’re going to keep it as the original local time (19:15:09), or if you’re going to convert to some standard time (e.g. 13:19:05 UTC if offset is +06:00).

It gets interesting if you need to convert that to your own local time – because it would depend on what DST rules were in place in 2009 at that time of the year – that can cause a real headache!

So, if you’re going to DateTime I recommend converting to universal time and then go from there. Add this to the test:

Console.WriteLine(result);
//little bit long winded - but you need the 'Universal' Kind for reliability
Console.WriteLine(
  DateTime.SpecifyKind(
    new DateTime(result.ToUniversalTime().Ticks), 
    DateTimeKind.Utc)
);    

This outputs:

11/16/2009 19:15:09 +06:00

11/16/2009 13:15:09