Z time is a term used to refer to Coordinated Universal Time (UTC) or Greenwich Mean Time (GMT), which is the standard time zone used in international aviation and marine navigation. However, there are several synonyms for this term, including Zulu time, Zulu hour, and Z time. These synonyms are commonly used in military, aviation, and navigation contexts to avoid confusion and ensure clear communication across different time zones. Other variants of this term include UTC+0, Alpha, and Zero Meridian Time. Regardless of their different names, they all refer to the same standard time used worldwide, primarily for global communications and travel.