# Time Zones on the Moon & Mars **URL:** \ **Category:** Factual Questions\ **Created:** [June 15, 2006, 1:35am UTC](https://boards.straightdope.com/t/time-zones-on-the-moon-mars/360755 "2006-06-15T01:35:48Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![rippingtons\_fan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rippingtons_fan/32/11767_2.png) [@rippingtons\_fan](https://boards.straightdope.com/u/rippingtons_fan)\ **Post date:** [June 15, 2006, 1:35am UTC](https://boards.straightdope.com/t/time-zones-on-the-moon-mars/360755/1 "2006-06-15T01:35:48Z")
Have scientists ever established time zones on the Moon and Mars to give an actual “local time” to where spacecraft are currently located? If time zones have been established, where (on the maps) are the Prime Meridians located? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 15, 2006, 2:06am UTC](https://boards.straightdope.com/t/time-zones-on-the-moon-mars/360755/2 "2006-06-15T02:06:56Z")
I know the rover operators have adjusted themselves to mars days (called Sols) and their work day is actually a mars work day. FWIM’s a mars day cycle is 25 hrs long. ---
**Author:** ![Cunctator](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Cunctator](https://boards.straightdope.com/u/Cunctator)\ **Post date:** [June 15, 2006, 2:27am UTC](https://boards.straightdope.com/t/time-zones-on-the-moon-mars/360755/3 "2006-06-15T02:27:30Z")
There are some details [here](http://en.wikipedia.org/wiki/Time_and_date_on_Mars) of time keeping procedures on Mars. ---
**Author:** ![Glaze](https://avatars.discourse-cdn.com/v4/letter/g/7c8e57/32.png) [@Glaze](https://boards.straightdope.com/u/Glaze)\ **Post date:** [June 15, 2006, 3:02am UTC](https://boards.straightdope.com/t/time-zones-on-the-moon-mars/360755/4 "2006-06-15T03:02:25Z")
I beleve that all NASA offplanet operations use GMT. Any need for use of local time would be built around local noon. As yet there are not enough operations on Mars to need to use time zones to coordinate actions. Time zones here on Earth only came about after rail travel made use of local too confuseing. By the way on the Moon a day is 28 Earth days long so each time zone would likely be 1 E-day long. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [June 15, 2006, 4:18am UTC](https://boards.straightdope.com/t/time-zones-on-the-moon-mars/360755/5 "2006-06-15T04:18:42Z")
> [@rippingtons\_fan](#): > > If time zones have been established, where (on the maps) are the Prime Meridians located? While time zones haven’t been established (AFAIK), prime meridians have been established on several terrestrial bodies in the Solar System for cartographic purposes. They’re chosen by picking some arbitrary geological feature: [ul] [li]On the Moon, the prime meridian is (roughly) the center of the near side.[/li][li]On Mars, the prime meridian goes through the center of the crater Airy-0.[/li][li]On Venus, the prime meridian goes through the Eve crater; it’s the dot in the center of the crater at the lower left of [this image](http://www.solarviews.com/cap/venus/alpha1.htm).[/li][li]On Mercury, the _twentieth_ parallel is the one that’s defined to go through a small crater named Hun Kal. “Hun Kal” means “twenty” in Mayan. Cute, huh?[/li][/ul] And so forth. The International Astronomical Union actually has a group of astronomers who update and refine extraterrestrial cartographic coordinates as better data becomes available. You can buy their [most recent report](http://www.springerlink.com/(ciah4cf2zw1ywmjglqi3i145)/app/home/contribution.asp?referrer=parent&backto=searcharticlesresults,5,8;) if you’re truly interested.