What is Time Zone

A time zone is an offset from the time in Greenwich, England. The time in Greenwich was known as Greenwich Mean Time (GMT). It is now known as Coordinated Universal Time (UTC). A time zone is specified in either an offset from UTC or a geographic region (e.g., PST). HH:MI prefixed with a plus or minus sign is used to specify an offset:

• + indicates an increase for the offset from UTC.
• - indicates a decrease for the offset from UTC.
• HH:MI specifies the offset in hours and minutes for the time zone.

The following example shows offsets of 8 hours behind UTC

The following example 2 hours 15 minutes ahead of UTC:

A time zone can also be specified as the geographical region. For example, PST indicates Pacific Standard Time. PST is 8 hours behind UTC. EST indicates Eastern Standard Time. EST is 5 hours behind UTC.

Datetime Datatypes and Time Zones

1. What is Time Zone
2. Database Time Zone
3. Session Time Zone
4. Time Zone Names