Informing Ecological Design, LLC

INFORMATION ABOUT DAYLIGHT SAVINGS TIME

In case you haven't updated the clock software on the PC acting as your SenseDat Meter datalogger, we’d like to summarize the issues.

Remember that our SenseDat Converter software uses the PC clock to time stamp the energy data records. If the PC clock is "not right" (from clock drift or from the impending Daylight Savings Time rule change), then your data will have the wrong time stamps, making it harder to relate events in the building to your data series.

The change in rules for Daylight Savings Time affects the PC clocks of Windows systems; older systems are expecting to change to daylight savings time in April and back in October and don’t use the new dates.

A helpful site that links to Microsoft but seems easier to navigate is: http://www.uic.edu/depts/accc/systems/daylight/windows.html

Scroll down to find the update components appropriate to your system.

System summary:

Windows XP systems with service pack 2 (SP2) and current updates do not need any repair
Windows 2000 systems can be fixed with a program called TZedit Click Here (instructions below).
Windows 98 systems can be fixed with a special program Click here.

NOTE: We have tested the Windows 2000 program. We have NOT tested the Windows 98 program, obtained from a third party vendor, Intelliadmin, www.intelliadmin.com We provide the Windows 98 software as a convenience, without guaranteeing performance.

If you choose to fix your Windows 2000 "once and for all", here are the instructions for the TZEdit use.

Unzip the files into a Windows program directory such as c:\Program Files\TZEdit
Apply the tzedit.exe process to your system:
1. Exit out of applications.
2. Run the executable tzedit.exe using Start > Run, provide the full path, for example: c:\Program Files\TZEdit\tzedit.exe
3. Your current time zone should be highlighted. Click the Edit button.
4. Set Start Day to Second Sunday, March.
5. Set Last Day to First Sunday, November.
6. Click OK.
7. Click Close.

You need to change your time zone twice using the Windows Date and Time Control Panel.
1. From the Start menu, click Settings > Control Panel and then click Date and Time.
2. Click the Time Zone tab.
3. Select a different time zone and click Apply.
4. Now, select your time zone and click Apply, then click OK.
5. Restart your applications.

MORE INFORMATION
DST rule change–your options, in preferred order (our recommendation)

A. Use the TZEdit program

B. Make the changes manually (we took these steps from an IBM site discussing the DST problem):

Adjust the system clock manually four times each year:

In mid-March, when the new rules start, set forward the clock by one hour.
In early-April, when the old rule would have started DST, the clock will need to be set back one hour. This is necessary because the change will already have been made manually three weeks earlier, so the change programmed for April must be cancelled.
In late-October, cancel the programmed clock adjustment by setting the clock forward one hour ( DST now runs for an additional week)
Finally, in early November when DST now ends, set the clock back one hour.

C Do Nothing: Your energy data will be off one hour for three weeks in the spring (until the date of the OLD time zone change) and one week in the fall.

CONTACT INFORMATION
Call 1-866-871-7904 (toll free) or email Kevin Little, klittle@iecodesign.com , if you have any questions about how our software date and time stamps records.