格林尼治标准时间(Greenwich Mean Time-GMT),是指位于英国伦敦郊区的皇家格林尼治天文台(observatory)的标准时间,因为本初子午线被定义在通过那里的经线(meridian)。自1924年2月5日开始,格林尼治天文台每隔一小时会向全世界发布调时信息(information)。1884年,国际天文学家(astronomer)代表会议决定,以经过格林尼治的经线为本初子午线,作为计算地理经度的起点,也是世界标准“时区”的起点。1884年10月13日, Greenwich Mean Time (GMT) refers to the standard time of the Royal Greenwich Observatory located on the outskirts of London in the UK because the meridian was defined as the meridian passing there. Since February 5, 1924, the Greenwich Observatory will release tweets to the world every hour. In 1884, the meeting of international astronomers decided that starting with the Greenwich-based warp meridian as the starting meridian, as a starting point for calculating geographical longitude, is also the starting point of world standard “time zone ”. October 13, 1884,