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Solutions for New Daylight Savings Time Rules in 2007 in PowerLogic ION PRODUCTS

Goals and Symptoms


Beginning in the spring of 2007, daylight saving time (DST) start and end dates in the United States and other jurisdictions will change. DST in these areas will start three weeks earlier (2:00 A.M. on the second Sunday in March) and will end one week later (2:00 A.M. on the first Sunday in November).

The following regions have new DST dates in 2007:
  • Newfoundland Time (Canada)
  • Atlantic Time (Canada)
  • Eastern Time (US & Canada)
  • Central Time (US & Canada)
  • Mountain Time (US & Canada)
  • Pacific Time (US & Canada)
  • Alaskan Time (US)
  • Central Brazilian Time (Manaus)
  • E. South America Time (Brasilia)
  • W. Australia Time (Perth)

Meter Impacts

New DST rules do not impact revenue meter data or how data is logged by ION meters or software. However, meters will require an update of their clock settings to adjust for new DST transition dates in order to display correct local time throughout 2007 and later on the meter’s front panel.

Software Impact

Microsoft has released a Registry update for Windows XP and Windows 2003 server that is required in order to have your computer correctly reflect the new DST transition dates. On updated machines, ION Enterprise will display correct local time in Vista, Webreach, and Reporter for data after the first Sunday in November 2006, and future. A hotfix is required to display correct local time before this date and during the four weeks each year when DST is not aligned with 2007 dates.

Customers in Mexico should confirm the time zone settings on their Windows system clock, as the Microsoft registry changes have created new selections for Mexican time zones due to Mexico retaining the same DST transition dates.

Facts and Changes


The following PRODUCTS are affected by changes to DST transitions dates:

  • All ION meters except ION6200, ION7300 and ACM3XXX.
  • ION Enterprise software
  • ION EEM software
  • Windows computers running ION Setup

How ION Systems Use Time Information

ION meters and software use UTC (Coordinated Universal Time) to record all time-stamped data. UTC is determined by the time zone offset that is configured in an ION meter’s Clock Module, or in software by the time zone offset of the computer’s Windows clock setting. UTC does not observe DST transitions.

When time-stamped data is displayed on the front panel of a meter, UTC timestamps are converted to local time using the time zone and DST information in the meter’s Clock Module.

When time-stamped data is displayed in ION Enterprise, the timestamps in the database are converted from UTC to local time based on the Windows system clock and information in the Windows Registry.

Information in the database is never changed based on DST settings; these settings are only used to convert the display from the UTC timestamps that are in the database.

Time-synchronization between ION Enterprise and ION meters uses UTC, and therefore is not affected by DST transitions.

Where DST transition information is stored

ION meters with internal clocks have a Clock Module that stores all time-related information. The Clock Module is typically configured with the local time zone of the meter’s installation location, and DST transition dates. Meters like the ION7700 store DST transition dates for one year, after which they must be updated. Other meters like the ION76xx can store 20 years of DST transition dates.

ION Enterprise and ION Setup software use the time zone and DST transition information provided by the Windows operating system.

Windows Registry Changes

On Windows computers, time zones and their respective DST transition rules are stored in the Windows Registry. When a user selects a time zone in the Windows clock, the Windows Registry determines the appropriate DST rule for that time zone.

Microsoft has released an update for the Windows Registry (KB928388) on Windows XP and Windows 2003 Server that updates time zone and DST transition information to include the new DST transition rules that are coming info effect in 2007 in the US and Canada. In addition, the registry has added a dynamic structure that allows software to lookup DST transition rules for prior years. Previously, Windows stored only a single rule for each time zone.

Causes and Fixes


ION Meters can be updated with correct DST transitions by using ION Setup v2.1 Build 660 or newer. Install this version on any Windows XP or 2003 Server machine that has been updated with the Microsoft Windows Update for DST. For other Windows Operating systems, consult your IT department on how to update the registry settings. ION Setup will use the information contained in the registry to automatically program the meter’s Clock module with correct DST settings.

ION Enterprise software requires a hotfix to interpret the new dynamic structure of the Windows Registry. This hotfix will allow accurate timestamp reporting for data prior to the 2007 DST transitions.

If the ION Enterprise hotfix is not applied, the system will use the 2007 DST transition settings for all data, including 2006 and earlier.

Click here to download the ION Enterprise 5.5 hotfix. (Only for 5.5 SP2)

Click here to download the ION Enterprise 5.0 hotfix. (Only for 5.0 SP5)

Note: This hotfix should be applied to the ION Enterprise Primary Server, Secondary Servers (if applicable) and client workstations. Also note, the 5.5 hotfix can only be applied to ION Enterprise 5.5 SP2. The 5.0 hotfix can only be applied to ION Enterprise 5.0 SP5.


Q: How do I update the DST settings in my ION meter?

A: Please refer to our online technical article or contact tech support directly at

Q: Why are the ION6200 and ION7300 not affected by DST?

A: ION6200 and ION7300 do not have a battery backed clock so they lose all date and time information when powered down. ION models 7330, 7350, 7550, 7650 and 8600 all have this feature which allows date and time information to remain intact even when power is lost.

Q: Will the DST solution work for my older meters like the ION7700, ION7500 and ION7600?

A: Yes. Use the same procedure as outlined in the online technical article or contact support directly at

Q: What versions of ION Enterprise will the DST hotfix work with?

A: The hotfix for version 5.5 will only work with ION Enterprise 5.5 SP2. The hotfix for version 5.0 will only work with ION Enterprise 5.0 SP5.

Note, that systems that have been updated with the Windows Registry DST update provided by Microsoft will continue to operate correctly through the DST transition on March 11.

Q: What if I have ION EEM?

A: Contact tech support with questions about EEM,

Q: How do I know if my computer has been updated with the Windows registry update?

A: View your Windows Date and Time Properties by double-clicking on the Windows Clock. Select the Time Zone tab, and view the list of available time zones. Your machine has been updated with the Microsoft Update if you can see a time zone called “(UTC -8:00) Tijuana, Baja California”.

Q: How do I update my Windows 2000 machine?

A: Mainstream support for Windows 2000 was ended in June 2005. Microsoft has developed a hotfix for Windows 2000 which has been released to customers who have purchased a Windows 2000 Extended Support agreement. Customers who do not have an Extended Support agreement can purchase this update directly from Microsoft.

Q: Can I manually edit my DST rules using on my Windows 2000 machine?

A: Tools are available that can edit the default DST rules provided by Microsoft. These tools can be used to update Windows 2000 machines with the 2007 DST rules, however these rules will overwrite the 2006 rules. Therefore this is helpful to allow your computer to continue to automatically display the correct time and for any reporting in 2007 and future, but any reports for data in 2006 and earlier will display incorrect local time for the 4 weeks of the year when DST is not aligned with 2007 dates. For instructions, refer to

Q: Where can I get more information about the 2007 DST changes in Windows?



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