Well, just for a briefing, since 1966, most of the United States has observed Daylight Saving Time from at 2:00 a.m. on the first Sunday of April to 2:00 a.m. on the last Sunday of October. But in 2007, most of the U.S. will begin Daylight Saving Time at 2:00 a.m. on the second Sunday in March and revert to standard time on the first Sunday in November.
So, Oracle has released patches to adapt these Daylight saving time changes. The databases that are using the following will be impacted…
1. Databases using TIMESTAMP WITH TIME ZONE and TIMESTAMP WITH LOCAL TIME ZONE data types and TZ_OFFSET function as they take their time zone information from Oracle's time zone files.