Evan Dodds - Microsoft Exchange Server Blog : Timezones

Great timezone post over at EHLO

evand — Tue, 29 Nov 2005 18:11:00 GMT

As a timezone fanatic, I can’t pass up an opportunity to link to this interesting post over at EHLO blog!

It talks about the specifics around how to deal with calendaring behavior in Outlook in those countries where timezones adjust for daylight saving time at different times each year. Good stuff!

Breaking News on the Daylight Saving Time issue!

evand — Fri, 22 Jul 2005 20:38:00 GMT

Breaking News at 9:55am PDT!

Hehe, not really that important, I suppose. But can you tell it interests me?

Someone (thanks Robert) pointed me to this article: http://www.msnbc.msn.com/id/8659492/ (and this associated update as well: http://www.msnbc.msn.com/id/8667052/)

So, the compromise appears to be that we’re going to switch daylight saving time by adding ONE extra month (four weeks), not two months. So it’ll start two weeks earlier (middle of March) and end two weeks later (first week in November).

It all seems a bit silly and complicated to me. I wonder why don’t we just switch to DST year round. And call it Standard Time. And just be done with it.

Heck, I’d even go so far as to say we should ditch timezones outright. Why not just do everything on GMT. I wouldn’t mind waking up at 11pm and going to bed at 2pm, it’s no different than I do it today; we just translate the time for some reason.

It also makes me wonder why they don’t have “date-zones” for the southern hemisphere. Doesn’t it seem strange that they celebrate christmas in the middle of their summer! Maybe they should shift their calendar months by 6 months so it “makes more sense” and for “parity with timezone behavior”. That would be pretty silly, wouldn’t it…

Anyway, according to the articles, principle concerns around the extra month were related to farmers’ concerns, school plans, Jewish prayer schedules, and international flight arrangements. One benefit of the extended ending of DST is that now Halloween will be under DST so it will stay light “later” while kids are trick-or-treating…

Change to Daylight Saving time in the US?

evand — Thu, 21 Jul 2005 17:52:00 GMT

Wow, so this is interesting: http://www.suntimes.com/output/news/cst-nws-daylight20.html. Evidently congress is/was considering changing Daylight Saving time in the upcoming “Energy Policy Act of 2005”. By this proposal, it would start in March and end in November instead of the current April->October.

And yes, they did actually call it “Daylight Savings”. Ugh.

Here’s the relevant text from HR.6 (or easier to read, probably here):

SEC. 111. DAYLIGHT SAVINGS.

(a) Repeal- Section 3(a) of the Uniform Time Act of 1966 (15 U.S.C. 260a(a)) is amended--

(1) by striking `April' and inserting `March'; and

(2) by striking `October' and inserting `November'.

(b) Report to Congress- Not later than 9 months after the date of enactment of this Act, the Secretary of Energy shall report to Congress on the impact this section on energy consumption in the United States.

But I’m not sure it’s going to happen. It looks like the Senate (in SA 775) agreed to totally toss the house document and replace it with their own (which doesn’t appear to have the Daylight Saving Time change). You can see the Senate amended version here. Also see the Senate original version of the “Energy Policy Act of 2005” S.10, which does not appear to mention Daylight Saving time at all.

Perhaps the Senate was so confused by calling it Daylight SavingS Time that they just dropped that section!

Microsoft Time Zone utility released

evand — Sun, 12 Jun 2005 20:19:00 GMT

I never thought I’d be posting so much about timezones; but in that spirit, I’m going to create a category for it in case there are other posts: http://blogs.technet.com/evand/archive/category/10087.aspx

Microsoft released the Microsoft Time Zone utility back in April (download here) with the following description:

Overview

Do you have relatives that live far away? Do you work with people from other countries? Use this simple utility to keep track of the time in other part of the world. Share your ideas without waking up your buddies. Microsoft Time Zone installs as a small tray icon that allows you to specify as many as five cities to watch the time on while you are working on your computer. In order to schedule meetings and trip the Microsoft Time Zone application also lets you compare times at different places in the world without changing your system time. With Microsoft Time Zone you will always know the time.

Uh oh, it's Daylight Saving Time again!

evand — Sun, 03 Apr 2005 20:17:00 GMT

If you read my post back in October, you already knew to set your clock ahead this morning. That’s good, as it means you’re probably also ready to start referring to everything in DST again.

Here’s the short reminder for the rest of you. Today starts Daylight Saving Time in the United States. As of this morning, we are no longer in Standard Time (in the vast majority of the US). Couple of quick scenarios for example:

If your email signature says you work 9–5 EST, now is the time to change it (hint: EDT).
If your voicemail says you’ll be “returning to the office on Monday at 8am Pacific Standard Time”, you should fix it (hint: you’ll most likely be “returning to the office on Monday at 8am Pacific Daylight Time”).

Good luck, America! You can do it!

Hooray for Eastern Standard Time!

evand — Mon, 01 Nov 2004 02:33:00 GMT

Well, I'm back from vacation and thanks to this morning's time change (at least in the US), very glad to be back into Eastern Standard Time! Warning: Timezone misunderstandings are a huge pet peeve of mine. Ask my friends. :)

This is the easy part of the year -- the half of the year where no matter how little someone understands timezones, they can blithely state that the meeting is at "2pm EST" or that they work "8-5 EST" and actually be right! During Daylight Saving Time (essentially, April -> October in the US), lots of people I interact with still refer to Eastern Standard Time, totally oblivious to the fact that they are referencing a different timezone than they're currently in.

So, here's the short version -- a pocket guide, if you will:

Greenwich Mean Time (GMT/UTC) is a fixed timezone. It never changes.
Eastern Standard Time (EST) is also a fixed timezone. It is (always) GMT-5:00.
Eastern Daylight Time (EDT) is also a fixed timezone. It is (always) GMT-4:00.

In (most of) the US, we simply jump back and forth an hour twice each year -- we switch into a different timezone. EST is always 5 hours behind GMT. EDT is always 4 hours behind GMT.

And here's the important thing: If you say the meeting is at 2pm EST... during July.... in Charlotte, NC... do you mean that we should show up at 3pm EDT? Should I just assume you don't understand timezones when I put the meeting into my Outlook calendar with a 2pm EDT start time? Computers understand timezones, of course!

See these links for additional information:

http://wwp.greenwichmeantime.com/time-zone/rules/usa.htm

http://wwp.greenwichmeantime.com/info/daylightsaving.htm

http://www.boulder.nist.gov/timefreq/general/misc.htm#Anchor-32566

http://webexhibits.org/daylightsaving/

(this post dedicated to Michael, Scott and Jodi - who get to listen to me rant on this topic at least twice each year). :)

Updated Jan 17, 2005 – I’ve written a utility that’ll tell you how your machine’s timezone settings are configured. This won’t tell you which timezone you’re in (that’d be a neat trick!), but it’ll tell you which timezone your machine is currently configured for plus all the DST stuff. Get it here.