How do I parse an RFC822 date in .NET?

Question

I have the following datetime string as returned to me by the Twitter API:

"Thu Apr 26 11:38:36 +0000 2012"

I need to convert this to a DateTime object so I call ParseExact with a custom format specifier:

CultureInfo provider = CultureInfo.InvariantCulture;
DateTime publishDate = DateTime.ParseExact(tweet["created_at"].ToString(), "ddd MMM dd hh:mm:ss zzz yyyy", provider);

However, this raise a FormatException exception for any variant of z, zz or zzz for the time zone:

String was not recognized as a valid DateTime.

Looking at the MSDN documentation it's clear that that format specifier is expecting the time zone to be in the format zz:zz where there is a colon in the time zone to delimit the hours and minutes.

I've checked other questions on Stack Overflow like:

and none of them really help.

Is there a time zone specifier I can use that will correctly parse this format?

Curious, I setup a test using your exact code without error. Well, except that I don't have the `tweet` field, of course, I just used the date string verbatim. — DonBoitnott, Jun 21 '13 at 11:38
Weird.. This doesn't throw any exception on my computer (VS 2008) (x86) (.NET 4.5) It doesn't throw also in [`Ideone`](http://ideone.com/mKywiy) — Soner Gönül, Jun 21 '13 at 11:39
Console application, targeting fw 4, runs your code perfectly (was 4.5, I re-targeted it. I'm on VS2012). Are you 100% sure about the contents of your "tweet[]" field ? — Alex, Jun 21 '13 at 11:41

score 4 · Accepted Answer · answered Jun 21 '13 at 12:02

4

Really silly this one.

The problem was the hour specifier. I'd used "hh" which is for 12 hour clock times. For 24 hour times I should have used "HH".

Note the subtle difference.

Changing that it all works as expected.

answered Jun 21 '13 at 12:02

ChrisF

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I think the answer here is much better than your way of doing it: http://stackoverflow.com/questions/284775/how-do-i-parse-and-convert-datetime-s-to-the-rfc-822-date-time-format – DermFrench Jun 04 '15 at 10:00
@DermFrench - that question is a more general one. With this I had a very specific problem which had a very specific cause - albeit one that could be quite common to make. – ChrisF Jun 04 '15 at 10:03
I just assumed the parsing in the other answer would work in your case as well - didn't test it. – DermFrench Jun 04 '15 at 11:14

How do I parse an RFC822 date in .NET?

1 Answers1