While I wasn't looking, Doug Purdy, who is the PM for the team in charge of the XmlSerializer has posted this little cryptic answer to my initial question:

String serializedDateTime = XmlConvert.ToString( someDateTime );

DateTime deserializedDateTime = XmlConvert.ToDateTime( serializedDateTime );

What Doug is showing is really what the serializer is doing with dates under the hood and that I am incorrectly blaming the XmlSerializer for the lack of UTC support. [XmlConvert.ToString() also does nothing more than calling DateTime.ToString() with the appropriate format string]. As I was already saying in yesterday's post, but what I want to make a bit clearer here again is that the actual problem is the lack of time-zone awareness in DateTime.

So the proper thing more me to do is to ask the base-class library team for time-zone support in the base-class library for Whidbey so that Doug can fix this for us ;)

I posted a little question here, just asking "Why?". For your reading convenience, I pull the code in here once more:

DateTime issued;

[XmlIgnore]
public DateTime IssuedUtc
{ get { return issued; } set { issued = value; } }

[XmlElement("issued")]
public DateTime IssuedLocalTime
{ get { return Issued.ToLocalTime(); } set { Issued = value.ToUniversalTime(); } }

So, indeed, why am I doing this? Well, when I decided to normalize all times handled by the backend engine of dasBlog into the UTC timezone, I really didn't think of the XML Serializer being a problem at first. It turned out to be one.

The reason why I wanted all times to be handled internally as UTC is quite simple: Too many time zones to deal with and I need to have a proper reference to do forward and backward time calculations. dasBlog deals with four time-zones:

• "Reader Time": The "<%userWhen%> macro emits a block of script that will cause the browser to emit the time of a post local to the reader's time zone. That one is easy, because the calculation happens on the client, but I need to feed it UTC (GMT).
• "Display Time": This is the time zone the blog owner selects for his/her blog. All times displayed on the weblog pages are shown in that time zone (complete with the TZ name and the GMT offset). This also applies to the "admin pages" such as referrals and events (which both roll over in synch with the display time zone). Display time is calculated dynamically and you will notice that it also automatically adjusts for daylight savings time. The display time zone is also by no means fixed. If the blog author travels (and you will see this on my blog starting next week), he/she can adjust the blog to his/her present time zone. When I am going to be at TechEd Malaysia, my blog will show UTC+0800. To make this time-zone shifting work, the absolute time must be stored in UTC.
• "Engine Time": This is UTC. All of the dasBlog runtime handles everything in UTC.
• "Server Time": Now were getting to the point. The engine runs on a server that has it's own local time zone setting: "server local time". That's something that the user who's running his engine at some ISP can't control and that's the one of all the time zones that really nobody is ever interested in. You shouldn't care whether your blog is hosted in Germany, the U.S. East Coast or Singapore. That's even more of an issue because one could expect that hosted sites may get moved around between ISP locations. The only little thing we're interested in is that the server knows its offset to UTC.

So ... I was thinking.... ask for DateTime.Now.ToUniversalTime(), handle everything in UTC from there on and everything's good. (Btw, I know about DateTime.UtcNow, but I like the expressiveness of this better).

What I wasn't considering is the way the XmlSerializer works, which I am using both for storage and for the various web services (including the Atom feed). What I also found is that the DateTime class in the framework isn't time-zone aware.

The workaround above is used because the XML Serialization infrastructure always assumes local time ("Server time") for serialization and will always emit ISO 8601 dates with a time-zone suffix like this: 2003-08-19T15:15:58.0781250+02:00. So when you are handling UTC times internally and use them blindly with XML serialization for both storage and web services, the serializer will assume you are using local time and throw you off by your own time-zone difference to UTC.

This isn't "too bad" when you store stuff in local XML files, because when you write something wrong from the same place you read it back into and your time-zones don't change you are in ok in memory, but you are nevertheless wrong on disk. What happened to me in dasBlog version 1.1 was that I was thinking that I stored UTC, but in fact I stored everything in local time. My UTC time 2003-08-19T15:15:58 always turned into 2003-08-19T15:15:58+02:00, because the DateTime class doesn't keep time-zone information around that the serializer could use. Therefore the serializer must always assume local time and that causes the offset to be emitted. That's of course much worse for UTC+12.

The fix:

The field  DateTime issued; holds the "engine time", which is always UTC. 

The property

[XmlIgnore]
public DateTime IssuedUtc
{ get { return issued; } set { issued = value; } }

wraps this value and is the property that the engine works with internally. The XmlSerializer is instructed to ignore this value in the serialization process by declaration of the [XmlIgnore] attribute. Instead, we tell the serializer to look at the following property, which is not used by the engine itself and also indicates that by its name suffix "LocalTime", which essentially declares it as "off limits" for direct access to everyone knowing the project:

[XmlElement("issued")]
public DateTime IssuedLocalTime
{ get { return Issued.ToLocalTime(); } set { Issued = value.ToUniversalTime(); } }

This property is the one that the serializer grabs and it does the proper conversion to and from server local time that the serializer requires. The actual dasBlog code is using a variant of this property that is a bit larger in code size because it also checks for DateTime.MinValue and DateTime.MaxValue occurrences, which, depending on the server time zone, would cause the time zone shifting to fail with an overflow/underflow exception (and no, I am not checking near MinValue and MaxValue):

So, that's why.

Be aware that all of this applies to ASP.NET Web Services, too, and if you are dealing with multiple time zones are you are using UTC normalized times in your app, you will have to deal with this. If "server time" makes you happy, you won't need to worry.

Ok, I couldn't resist getting the Arabic support (mostly) right. Malek helped me and by what he tells me, we've succeeded mostly. There are a few things left to do around wildly wrapping symbol characters, but that'll be worked out eventually.

So, this little patch updates dasBlog with French, Russian and Arabic, including full right-to-left reading support, which the engine injects appropriately into the <body> tag (dir="RTL") based on a hint in the Arabic resource table.

On the download site I posted add-on packs for French language support and the first steps toward Arabic language support, which are the string tables. My friend Malek Kemmou from Morocco wants to help me figuring out how we can make right-to-left reading work "magically" and without having to rework all the templates. He also did those two translations. Thanks!

Update: I added a first attempt at generic RTL support to my private build and installed it here. If the primary language is set to any of the Arabic language variants, the page will flip into RTL reading. There are some issues around formatting to be worked out, though.

The workspace is maxed out at the current 20 users. I already submitted the form to ask for more users (the largest decimal number it takes is 99 so I went for that) and I really hope that there's someone at the other end of that form. GDN team, are you listening?

Update: Fixed.

I am sure it's a coindicence, but every once in a while I get referrals from some invisible site inside www.iaea.org.

Therefore, I hereby declare that I support only "Atom the XML format" and not "Atom the bomb". My house is open for inspections, if you guys think that's necessary.

I hope that keeps me out of trouble. 

The language list is growing; Tom Mertens and Bart Vermeersch both sent me Dutch string tables for inclusion in dasBlog 1.2. One is going to be the default for Dutch and Dutch (Netherlands) and the other is going to be the default for Dutch (Belgium).

Bedankt! Site updated.

Note: For visitors of your site, this entry is only displayed for users with the preselected language English/English (en)

Error:
System.ArgumentException: Culture name en;q=1.0 is not supported.
Parameter name: name
at System.Globalization.CultureInfo..ctor(String name, Boolean useUserOverride)
at System.Globalization.CultureInfo.CreateSpecificCulture(String name)
at newtelligence.DasBlog.Web.Core.SharedBasePage.SetupPage(Object o, EventArgs e)
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Web.UI.Control.OnInit(EventArgs e)
at newtelligence.DasBlog.Web.HomePage.OnInit(EventArgs e)
at System.Web.UI.Control.InitRecursive(Control namingContainer)
at System.Web.UI.Page.ProcessRequestMain()
while processing ht tp://staff.newtelligence.net/clemensv/default.aspx?external_referrer=ht tp://newtelligence.com/.

To whoever caused this event log entry to show up 10 minutes ago .... thanks, should be fixed now ;)

Download: Web.StringTables.resx
Download: WebControls.StringTables.resx
Download: WebCore.StringTables.resx

Since the backend stores all times in UTC, the engine can also adjust for daylight savings time when rendering. Check out the April 1st page and compare the timezone info below the entries with the following March 30th.

(BTW, I've done the whole time handling stuff mostly because I've seen that being only on GMT is a bit painful if you are a Fast Chicken in NZ. Nic, you get your timezone back.)

Don't be surprised to see this Weblog showing you Russian day and month names if your browser's preferred language is set to Russian or talks to you in Spanish or Italian. Also, don't be surprised if even more things (like the "Comments" link or all the field names on the Comment page) show up in German, if your preferred language is German. That's a feature. 

This is a split entry consisting of two posts. Everyone can see this post, but you will not see (2/2) on the website, if your browser's "Languages" setting doesn't have German as an acceptable language.

Here's a CERT advisory to check out regarding the vulnerability of other DCE implementations to the Blaster worm. And unless otherwise stated on their site (which isn't the case now), I would assume that Software AG's EntireX DCOM is vulnerable as well.

Can't be referenced too much.... so here's the link: http://www.microsoft.com/security/incident/blast.asp. And here's Symantec's info and the removal tool.