Date Time Terminology |
BCE |
Before Common Era |
BCRS |
Barycentric Celestial Reference System
(Geocentric - GCRS) |
BCT |
Barycentric Coordinate Time |
CDC |
Century Date Change (19xx to 20xx etc.) |
CST |
Central Standard Time (central part of USA) |
EST |
Eastern Standard Time (eastern USA) |
GAST |
Greenwich Apparent Sidereal Time |
GAT |
Greenwich Apparent Time |
GCRS |
Geocentric Celestial Reference System
(Barycentric - BCRS) |
GCT |
Geocentric Coordinate Time
(aka
TCG) |
GMT |
Greenwich Mean Time (same as
UTC) |
GMST |
Greenwich Mean
Sidereal Time |
GST |
Greenwich Sidereal Time |
ICRF |
International Celestial Reference Frame |
ICRS |
International Celestial Reference System |
IDL |
International Date Line (line where the day begins) |
IERS |
International Earth Rotation Service (established in 1987) |
IRM |
IERS
Reference Meridian |
ITRS |
International Terrestrial Reference System |
LOD |
Length of Day (60 x 60 x 24 = 86,400 s) |
MST |
Mountain Standard Time (mid-west part of USA) |
PST |
Pacific Standard Time (pacific/western part of USA) |
TCG |
Geocentric Coordinate Time |
TDT |
Terrestrial Dynamical Time (time based on an atomic scale for astronomical computations) |
TZO |
Time Zone Offset |
UTC |
Coordinated Universal Time (same as
GMT) |