| Details: | Reminder, Time Problems Could Happen to You on March 11:
Another reminder that one week from today, Daylight Saving Time officially begins in North America, which is 2 weeks earlier than previous years.
In mid-2005, the US government announced Daylight Saving Time will change from the first Sunday in April to the second Sunday in March.
Software developers began issuing updates preparing for this change since it was announced.
If you have a computer or device which has not received an operating system update in a while, you may want to update it soon or the device may have an incorrect clock on March 11.
Devices and computers which may be at risk:
- Any electronic device purchased before 2006 with a built-in calendar and clock which automatically adjusts for Daylight Saving Time.
Check with the manufacturer of the device for system updates, or you may need to manually adjust its clock 4 times every year (this year on March 11, April 1, October 28, and November 4).
- Any laptop or desktop computer purchased before 2006 with automatic updates disabled or without access to the Internet.
- Servers installed prior to 2006 are likely vulnerable, because most servers do not automatically download system updates.
The servers which can cause most havoc are those which do email, groupware, database, and web servers.
- Java based applications and systems which have not been updated in the last year.
This includes JDK and JRE version 1.4.2 and earlier.
- Phone Systems and telecommunications equipment (including some phones and fax machines).
- Some VCRs, DVRs, DVD Recorders, timed security systems, and punch clocks with built-in calendars.
- Most Blackberry servers and portable devices.
Devices which are likely safe:
- If your computer runs any legal version of Windows or Mac connected to the Internet, it probably has this update installed through the operating system's automatic update feature.
- Computers with Windows Vista.
- Portable electronic devices which receive automatic updates through the Internet, through a telephone modem, or over airwaves.
This includes mobile phones, cell phones, and CallerID boxes.
- DVRs which receive daily or weekly updates, such as Tivo and Motorola DVRs, and other cable boxes supplied by your cable/satellite provider.
- Routers and Managed Switches.
Although most do have built-in calendars, they should continue to operate normally even if they display an incorrect local time.
- Clocks which never adjust themselves for Daylight Saving Time automatically, such as most home telephones, some answering machines, appliances, and most wall clocks.
Of course these are devices which you adjust manually anyway.
- Devices located exclusively within Arizona, Hawaii, Puerto Rico, Virgin Islands, Guam, and American Samoa, because they never observe Daylight Saving Time.
Most people leave servers alone after initial install, and thus can cause havoc all over the Internet next week.
Nearly all databases (MySQL, Oracle, and SQL Server) rely on the clock of the server where installed, so keeping the system's clock correct will protect most databases.
In some very rare cases, a database may be specifically configured to use an internal clock rather than clock on the system, and those will require a Daylight Saving Time update into the database itself.
An example would be a database which serves people in New York and uses Eastern Time, but the server is physically located in England with a system clock in British Time.
Any computer which synchronizes its clock with a time server (such as NTP) is still vulnerable.
More information:
- General Information on Daylight Saving Time by Microsoft.
- Timezone Updates for Microsoft Windows Operating Systems from Microsoft.com.
Or you can install a Daylight Saving Time Fix yourself.
- Microsoft Exchange Server Timezone Fix.
- Microsoft Outlook Timezone Fix.
- Blackberry Daylight Saving Time Update for servers and Blackberry devices.
- For most Linux operating systems, run this command from a shell prompt to confirm your clock will correctly update on March 11 and Nov 4:
/usr/sbin/zdump -v America/New_York | grep 2007
It does not matter if New York is your timezone since the date is what's important here, but you could use America/Los_Angeles or whatever timezone your system uses.
If Apr 1 and Oct 28 appear, then the timezone file is incorrect.
An update to the Linux tzdata package can be obtained through the maker of your Linux operating system (eg. Redhat.com or FreeBSD.org), finding your update on Rpmfind, using "yum", or some other system update utility.
- Mac OS X Software Update from Apple.com, download and install the Daylight Saving Time Update manually.
An automatic way is to click the Apple icon on the upper-left of your screen, then "Software Update", and install the latest OS X Server Update.
You may need to repeat the Mac's server update until all relevant updates are installed.
To check if the Daylight Saving Time update is already installed, use the above "/usr/sbin/zdump" linux command.
- Sun Java Timezone Update
- Lotus Notes Timezone Update
- Cisco Fix using a "clock summertime" command.
Preparing for this Daylight Saving Time change this week will likely save you time and money fixing broken apps and servers next week.
System administrators should update all computers and portable electronic devices prior to March 11 to avoid things breaking.
Individual users should be aware that even though the clock on your computer may read the correct time after March 11, other people may have incorrect clocks, and some of your portable devices and some networked applications may have incorrect clocks until manually adjusted or fixed.
Examples of problems which can occur on & after March 11:
- Your portable calendar device (Blackberry, Palm, or Windows CE device) may fail to spring its clock forward on March 11, and will remind you of an appointment one hour late.
- Electronic wakeup calls could occur one hour late.
- If a doctor's office schedules appointments using an electronic scheduling system, but the appointment is actually scheduled one hour earlier or later, it could cause patients to arrive at incorrect times.
- Banks, store receipts, and online purchases can record incorrect transaction times.
- Airline, train, and bus times may be missed, especially on March 11 and 12th when many people are unaware of the early time change, and for foreign travel agencies who are unaware of the time change.
- Phone systems may label voicemail and calls with incorrect times, causing confusion in the workplace.
- Email which relies on local time rather than a UTC offset may fail to be delivered.
Additionally, email delivered with incorrect times could be marked as spam or fail to appear in inboxes.
For the current official US Time, see Time.gov. |
