загадочная Z

[Claire80]

Пожалуйста, нужна ваша помощь. При обозначении даты и времени рейса самолета имеется запись
15JAN/2100Z , где первое - это дата, а второе - время. А что обозначает Z
может время по Гринвичу.
Заранее спасибо

[mahavishnu]

Совершенно справедливо:
Greenwich Mean Time; Time zone 7.5 W - 7.5 E (Greenwich Mean Time);

[Claire80]

спасибо огромное

[watchkeeper]

UT, Universal Time also called Zulu (Z) time, was previously called Greenwich Mean Time, GMT. It is based on the imaginary "mean sun," which averages out the effects on the length of the solar day caused by Earth's slightly non-circular orbit about the sun. UT is not updated with leap seconds as is UTC. Its reference point is also Greenwich, England: when it is noon on the prime meridian, it is noon (12:00:00) UT.
It is common to see outdated references to GMT, even in currently operating flight projects. It is also common to encounter references to UT or GMT when the system actually in use is UTC, for example, "Uplink the command at 1801Z."

http://www2.jpl.nasa.gov/basics/bsf2-3.html