The U.S. Energy Policy Act of 2005 extended Daylight Saving Time (DST) in the U.S. by approximately four weeks. As a result, beginning in 2007, DST will start three weeks earlier on March 11, 2007, and end one week later on November 4, 2007, resulting in a new DST period that is four weeks longer than previously observed.
If your computer runs on an American or Canadian Timezone setting this situation affects your computer and software.
The Basics
Daylight Saving Time (DST) will now 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).
| Previously started |
With the new law, will start |
Previously ended |
With the new law, will end |
| First Sunday in April |
Second Sunday in March |
Last Sunday in October |
First Sunday in November |
| Would have been: April 1, 2007 |
Will now be: March 11, 2007 |
Would have been: October 28, 2007 |
Will now be: November 4, 2007 |
What Microsoft Says
Quoted from the
Microsoft website "Preparing for daylight saving time changes in 2007":
Unless certain updates are applied to your computer, it is possible that the time zone settings for your computer's system clock may be incorrect during this four week period. This depends on where you live and which time zone you have selected. To see the time zone settings on your computer, follow these directions.
What about Paessler Products?
Basically both our monitoring products
IPCheck Server Monitor and
PRTG Traffic Grapher utilize the system clock at all times to get the current time. This means that both products depend on the daylight saving setting of your PC.
IPCheck Server Monitory
IPCheck Server Monitor has an option to set the system's clock via NTP. In this case the system gets its time setting from the NTP server (IPCheck checks the time once per hour).
Having a system with a remote probe which runs on a different timezone/daylight saving setting as the IPCheck server is no problem, the whole timestamp stuff is performed on the server only.
It is recommended to restart the IPCheck Server after installing the Daylight Saving Fix on your windows System (if it not already installed).
On the day in spring when the clock is set forward (the time jumps from 2 a.m. to 3 a.m.) you see no monitoring results or graphs between 2 and 3 a.m.
PRTG Traffic Grapher
On the day in spring when the clock is set forward (the time jumps from 2 a.m. to 3 a.m.) you will see a coverage of 96% for the whole day and no monitoring results or graphs between 2 and 3 a.m.
On the day in fall when the time is set one hour backward (i.e. the day has 25 hours) the measurements measured in the second instance of the hour between 2 a.m. and 3 a.m. is ignored for reports, except for SNMP traffic and other SNMP counter based sensors which show a peak with the data volume of the second instance in the last intervall before 2 a.m. and the first intervall after 3 a.m. Note: If you are using a spike filter, this may filter out this data!