Is ZXTM affected by the US Energy Policy Act?

This FAQ entry only affects customers running ZXTM in the US and Canada.

Amendments made in the US Energy Policy Act of 2005 affect the start and end dates of daylight saving time. These amendments begin in 2007, with the change to summer time now on the second Sunday of March (rather than the first Sunday of April). Canada follows the US on daylight saving time, so is affected by this too.

ZXTM uses daylight saving time information to ensure that the correct time is printed in log files, access log files, and various TrafficScript functions. Traffic handling is not affected by daylight saving time changes.

ZXTM Software customers

ZXTM software versions use daylight saving time information from the base Operating System. Customers should confirm that their OS correctly handles the new start and end dates, e.g. on Linux you can verify using the date command.

$ TZ=US/Pacific date -d "Mar 10 12:00:00 GMT 2007"
Sat Mar 10 04:00:00 PST 2007
$ TZ=US/Pacific date -d "Mar 11 12:00:00 GMT 2007"
Sun Mar 11 05:00:00 PDT 2007

In the above example the new daylight saving time dates are correctly handled (note the change from PST to PDT).

ZXTM Appliance customers (versions 4.1 and later)

ZXTM Appliance 4.1 (and later versions) correctly handle the new daylight saving time dates.

ZXTM Appliance customers (version 4.0)

ZXTM Appliance 4.0 does not handle the new daylight saving time dates. Customers running a 4.0 appliance in the US will notice that log files will be an hour out for a couple of weeks at the end of March.

Customers are recommended to upgrade to 4.1.

Crispin Flowerday [Zeus Dev Team] 10 January 2007