Manually configure daylight saving time dates by modifying an existing time zoneTo manually modify time zone settings by using the Time Zone Editor, follow these steps:
1. Start Time Zone Editor.
2. In the Time Zones list, select a time zone, and then click Edit. For example, click (GMT-08:00) Pacific Time (US & Canada); Tijuana, and then click Edit.
3. In the Edit Time Zone dialog box, click to select the Automatically set Daylight Saving Time check box.
4. Specify the correct daylight saving time start date and end date. To do this, follow these steps:
a. In the Start Day box, click the number of the day, the corresponding day of the week, and the month that you want. For example, click Second, click Sunday, and then click March.
b. Select the time that you want to start daylight saving time. For example, select 2:00 A.M.
c. In the Last Day box, click the number of the day, the corresponding day of the week, and the month that you want. For example, click First, click Sunday, and then click November.
d. Select the time that you want to end daylight saving time. For example, select 2:00 A.M.
e. In the Daylight Bias list, select how long you want the time to change when daylight saving time is in effect. For example, to set the clock forward 1 hour, leave the default setting of +1:00.
f. Click OK.
g. Select another time zone that has changed, and then repeat steps a-e. For more information about the time zones that have changed, click the following article number to view the article in the Microsoft Knowledge Base:
942763 December 2007 cumulative time zone update for Microsoft Windows operating systems
Repeat steps a through f for every time zone that has changed. When you have finished, click Close.
h. Click Start, point to Settings, point to Control Panel, and then double-click Date/Time.
i. Click the Time Zone tab.
j. Select a different time zone than the (GMT-08:00) Pacific Time (US & Canada); Tijuana time zone, and then click Apply.
k. Click (GMT-08:00) Pacific Time (US & Canada); Tijuana, and then click OK.
Note Steps 4j and 4k are required for the new changes to take effect.
In this example, steps 4a through 4f update the time zone database. Steps 4h through 4k force Windows to read the time zone database and copy the updated information into the TimeZoneInformation registry key in the current control set.