For Semmes Alabama:
August 21, 2017:
Start of partial eclipse: Noon
Maximum eclipse: 1:32 PM
End of partial eclipse 2:59 PM
UT or “Universal Time” is a single time standard that applies to all locations on Earth as opposed to your local time which will vary depending on your location (longitude). For all practical purposes, UT is equivalent to GMT (Greenwich Mean Time) which establishes a line of longitude that passes through Greenwich England (called the Prime Meridian) as the standard from which all other times are measured and UTC (Coordinated Universal Time) which is based on International Atomic Time (time measured very precisely as vibrations of a cesium atom).
The following chart may be used to convert UT to your US time zone during the eclipse.
Example: 18:23 UT = 12:23pm MDT