What is UTC?
Scientific convention dictates that data collected for global dissemination
be referenced to the internationally recognized Universal Time Coordinate (UTC).
UTC, also referred to as Zulu (Z) or Greenwich Mean Time (GMT), is
referenced to a clock in Greenwich, England.
As of 11:41p.m. CST on October 4, 2003 users of data displayed on the LUMCON
Monitoring System web site will be given the option of displaying graphic data
in either local time (CST or CDT) or the UTC standard . Tabular data on the
leader page for each station, as in the past, will be viewed in local time
(CST or CDT) only.
UTC uses a 24-hour clock instead of a 12-hour clock. For example 1:00 a.m. is
expressed as 0100 UTC and 1:00 p.m. is expressed as 1300 UTC.
To convert UTC to local time in the US Central Time Zone (where LUMCON is located), subtract 6 hours from UTC for times between 2 a.m. CST on the first Sunday in October and 2 a.m. CST on the first Sunday in April. For all other times of the year subtract 5 hours from UTC to get CDT.
To convert UTC to local time (Central Time), subtract 6 hours from UTC or five hours for convert from Central Daylight time. The table below shows North American conversion factors:
Local Time |
Subtract from UTC: |
| Atlantic Standard | Four hours |
| Atlantic Daylight | Three hours |
| Eastern Standard | Five hours |
| Eastern Daylight | Four hours |
| Central Standard | Six hours |
| Central Daylight | Five hours |
| Mountain Standard | Seven hours |
| Mountain Daylight | Six hours |
| Pacific Standard | Eight hours |
| Pacific Daylight | Seven hours |
| Alaskan Standard | Nine hours |
| Alaskan Daylight | Eight hours |
| Hawaiian Standard | Ten hours |
For more information:
The National Data Buoy Center's Explanation
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