6 November 2021

When Daylight Saving Time ends tonight our time zone will move one hour closer to Zulu Time.

Zulu (Z) Time is the aviation and military name for Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC). Wikipedia explains that back in 1950, when time zones were identified by successive letters of the alphabet, the Greenwich time zone was marked by a Z as the point of origin.  Z in the military alphabet is called “Zulu.” Z time = GMT = UTC.

Pilots use Zulu Time for navigation described in the video below. The internet and your cellphone use Z time behind the scenes.

Time Zones around the world are a patchwork based on local laws. Most of the world does not participate in DST though more than half of the world used to. This morning’s screenshot from timeandate.com (6 November 2021, 4:45 EDT) will look different in North America tomorrow morning. Click here to see how the colors changed in North America on 11 Nov 2021.

I’m not a fan of changing the clocks and wouldn’t mind if we changed them tonight and never changed again. 🙂

Further reading:

• Click here for the NATO phonetic alphabet where A,B,C… is Alpha, Bravo, Charlie…
• Example of internet Z time: When I download my cellphone photos from Google to my computer they are labeled in Z time, not in the local time they were taken by my cellphone.
• Most of the world does not participate in DST. Light gray areas on the map stopped participating, dark gray never used DST.

(photo of clock and map of DST from Wikimedia Commons. Time zone map is a point-in-time screenshot from timeanddate.com. Click here to see the current Time And Date map.)