Getting exception when using DateTime.Parse method - c#

So, i have this string "Date: Mon Jan 03 2011 19:29:44 GMT+0200", and when i use DateTime.Parse(date).ToString(); i'm getting "String was not recognized as a valid DateTime."
If i remove the '+0200' part it works ok, but ofcourse it doesn't show the correct local time.
What's wrong with that?

From the documentation, it seems that DateTime.Parse() only understands:
The GMT designator, used alone, e.g. Mon, Jan 03 2011 17:29:44 GMT, or
A time zone offset specified without the GMT designator, e.g. Mon, Jan 03 2011 19:29:44+02:00.
You might want to convert your date string to the second form.

It just means that the time zone offset isn't an expected part of the default format strings.
If you know what format you're expecting, I suggest you call DateTime.ParseExact (or DateTime.TryParseExact), specifying the format(s) to try. Look at the documentation for custom date/time format strings for more details.

You have two mistakes.
First - don`t use Parse method. More correct is TryParse.
Second - you will have globalisation issues, when you use Parse or TryParse without arguments.
For example, see this code:
DateTime.Parse( "01.02.2011" ); In the USA it is 2nd of January. In the Germany it is 1st of February.
So, I recomment you to use formats from this article.

Related

Bug in .NET's DateTime.ToString("R") with UTC dates?

I'm based in the UK (GMT+1 time at the moment).
If I run this:
> DateTime.UtcNow.ToString("R") // Or...
> DateTime.Now.ToUniversalTime().ToString("R")
"Mon, 06 Oct 2014 10:20:00 GMT"
Correct answer.
If I now run the same, without UTC DateTime conversion:
> DateTime.Now.ToString("R")
"Mon, 06 Oct 2014 11:20:00 GMT"
The time printed is correct, but the timezone is wrong. I would expect instead:
"Mon, 06 Oct 2014 11:20:00" // Or..
"Mon, 06 Oct 2014 11:20:00 BST"
Question: Is this behaviour by design? Can I get the same output as with the "R" format, but with the correct timezone indicator?
It's definitely not a bug, it's the documented behaviour:
The custom format string is "ddd, dd MMM yyyy HH':'mm':'ss 'GMT'". When this standard format specifier is used, the formatting or parsing operation always uses the invariant culture.
...
Although the RFC 1123 standard expresses a time as Coordinated Universal Time (UTC), the formatting operation does not modify the value of the DateTime object that is being formatted. Therefore, you must convert the DateTime value to UTC by calling the DateTime.ToUniversalTime method before you perform the formatting operation. In contrast, DateTimeOffset values perform this conversion automatically; there is no need to call the DateTimeOffset.ToUniversalTime method before the formatting operation.
As I noted in a comment on the question, 10:20 GMT is correct, assuming that you ran the code shortly before asking the question: 11:20 GMT has not occurred yet.
So basically, when you follow the guidance in the documentation and call ToUniversalTime, it does the right thing. When you don't, it gives a misleading value - that's unfortunate, but part of the broken design of DateTime IMO.
You should consider at least using DateTimeOffset, or potentially using my Noda Time project instead.

Troubles parsing DateTime from string

I am currently trying to parse a string that is obtained from an xml that is downloaded from the web every few minutes. The string looks like this:
Thu Jul 12 08:39:56 GMT+0100 2012
At first I just did a string.split and took out everything after the time (GMT+0100 2012) and inserted 2012 after the date.
This worked great until the date changed to:
Thu Jul 12 08:39:56 GMT+0000 2012
So I would like to dynamically pasre the GMT+ whatever as they send me that string in c#.
Any advice would be appreciated.
You can use DateTime.ParseExact with a custom date and time format string:
DateTime.ParseExact("Thu Jul 12 08:39:56 GMT+0000 2012",
"ddd MMM dd hh:mm:ss 'GMT'K yyyy",
CultureInfo.InvariantCulture)
This will throw a format exception if the string and format string do not match exactly, so you may want to use DateTime.TryParseExact that will return a false if it fails.
Instead of DateTime you may want to use DateTimeOffset that preserved timezone information , as #Keith commented - this may be important to your application.
Two things you can do: First, you should be able to use a custom format string with a ParseExact method, either from DateTime or DateTimeOffset (I would use DateTimeOffset if the actual time zone of the stamp is important, and not just the equivalent time in UTC or your local time zone).
Have a look: DateTime custom format string
The format string would probably be something like #"ddd MMM dd HH:mm:ss 'GMT'zzzz yyyy".
However, there's one snag; the .NET time zone offset ("zzzz" or simply "K") always includes a colon between the hour and minute when expressed as a string, which your input strings do not have. There is no way I know of to specify that the time zone offset doesn't/shouldn't have this colon, and I'm pretty sure that trying to parse it without a colon would cause an error.
The simplest workaround is to remove that specific colon from the string prior to parsing it. The code for that given your input is simply to remove the last colon character in the string:
var updatedString = inputString.Remove(inputString.LastIndexOf(':'), 1);
Try DateTime.Parse method to parse your date.
This should work:
XmlConvert.ToDateTime(textBox1.Text, "ddd MMM dd HH:mm:ss 'GMT'zzzz yyyy");

How to convert a string containing a EDT related instant to a DateTime?

I have a string in this format:
"Fri, 18 Mar 2011 18:53:15 EDT"
I want to convert this to datetime object, the problem is with EDT, at the end. If I use GMT DateTime.TryParse works fine, but if it is something else like EDT, it return false.
Check out the TimeZoneInfo class and this question, or the definitive time zone guide.

DateTime to RFC-1123 gives inaccurate timezone

If I get the RFC-1123 formatted date of a DateTime object, it gives the current local time, but gives the timezone as GMT (which is inaccurate).
DateTime.Now.ToString("r");
returns
Fri, 12 Feb 2010 16:23:03 GMT
At 4:23 in the afternoon, but my timezone is UTC+10 (plus, we're currently observing daylight saving time).
Now, I can get a return value that's "correct" by converting to UTC first:
DateTime.UtcNow.ToString("r");
returns
Fri, 12 Feb 2010 05:23:03 GMT
However, ideally, I'd like to get the right timezone, which I guess would be
Fri, 12 Feb 2010 16:23:03 +1100
Passing in the current CultureInfo doesn't change anything. I could get a UTC offset with TimeZoneInfo.Local.GetUtcOffset(...) and format a timezone string from that, but stripping out the GMT bit and replacing it seems gratutiously messy.
Is there a way to force it to include the correct timezone?
The .NET implementation always expresses the result as if it were GMT, irrespective of the time offset of the actual date.
By using DateTime.Now.ToString("r"); you're essentially saying String.Format("ddd, dd MMM yyyy HH':'mm':'ss 'GMT'", DateTime.Now);, which is the .NET RFC1123 format string, as indicated on MSDN - The RFC1123 ("R", "r") Format Specifier.
To get the behaviour you require, you should probably use String.Format, and replace the fixed 'GMT' section of the specifier with a time offset specifier:
The "z" Custom Format Specifier
The "zz" Custom Format Specifier
The "zzz" Custom Format Specifier
You could just do DateTime.UtcNow.ToString ("R"), you will still get GMT timezone but the time is correctly offset then.

Why isn't telligent's RSS.Net fork parsing dates?

I'm using Telligent's RSS.Net fork to parse an XML Stream. The stream is well-formed and most of the desired elements are being parsed, but for some reason the pubData element isn't.
Inspecting the feed contents shows the pubData element nicely displayed, no issues with the RSS or the element contents. But... As I said, no parsing, either. Inspecting in Visual Studio shows:
PubDate = {1/01/0001 12:00:00 AM}
Which is clearly not the case and suspiciously generic for an plain incorrect parse, so I suspect it's just failing outright and defaulting to the NYE culmination, 1 (Grab the nearest hot person, quick! *{Snog}*)
The feeds I'm trying to parse are Google News feeds, so I'd like to assume they're working correctly.
Aha!
On a hunch I checked through the RSSReader code, and found that the date parsing, when dealing with a date that doesn't parse cleanly (Say, GMT+Offset):
Mon, 02 Nov 2009 12:34:56 GTM+10:00
Will remove the last 5 characters, leaving:
Mon, 02 Nov 2009 12:34:56 GTM+
Which make DateTime.Parse very very sad.
So, I'm going to alter the library to deal with the GMT time offset.

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