There is probably a very simple and obvious answer to this question, but I’m coming up blank: How do they know what time it is on Mars?
From here:
They’re going by the position of the sun in the Martian sky. Nothing fancy or official.
Well, it was too vague to be official anyway, but Mars does have a prime meridian, so there is an official Mars time. See http://pweb.jps.net/~tgangale/mars/other/allison3_frm.htm for some stuff…
Local Mars time is easily determined. When the sun is at its zenith in the sky over the lander, it is exactly local noon. AFAIK, there are no time zones on Mars (just as all times were 'local; or ‘town’ time on Earth, not so long ago). There’s no need for them, but if you wanted them, they would be arbitrarily set by the user of the data (railroads, tasked with setting schedule tiems properly for thousands of stations, were among the big proponents of our current time zones. The average man didn’t care - to him it was whatever time the prevailing system said it was; who cared about the details?)
Planetary Mars time is simply a planet-wide ‘time zone’, set by the relevant user of that data (e.g. NASA), as above. There would be no harm if each user had their own ‘official’ time, as long as the conversion was known (and even that would only be needed for the few Mars collaborations.
One could think of “Mars Planetary time” as defining a prime meridian - i.e. whereever Mars noon equalled local noon.
Helpful link, with definitions, and software.
There are indeed time zones on Mars.
They are defined as 15degree wide slices of longitude centered on 0 15 30 etc.
The longitude lines themselves are the zone borders since we have no areopolitical borders to contend with (yet).
There is a cool little applet found
here that will solve all your questions.
Has Mars avoided Daylight Savings Time? What would it cost to move there?
Sadly, Mars lacks an international date line due to its having no nations for it to be inter of 
slight hijack:
I was searching the Web yesterday for something that would show me the current distance between Earth and Mars, because I was wondering how long the transmissions from the Rover take to get here. I couldn’t find anything. Does anyone know either of those factoids (current distance or transmission time) or know of a resource that will tell what the current distance is?
Thanks.
They said 10 minutes on the news.
Mars is way further than 10 minutes away. 2 1/2 - 3 hours at least, and that’s without the pit stops.
Mars is at most 234 million miles from the earth. At the speed of light that is 21 minutes, give or take.
if the copy of Celestia on my PC is correct,
Mars is currently 1.1862 AU distant from the Earth, or 177,453,000 kilometers.
SF worldbuilding at
http://www.orionsarm.com/main.html
Which is 9min 52sec as the photon flies.
I thought radio (or what) traveled at the speed of light. If the sun is 93 mil miles away light takes about 9 mintes???
How could mars radio take 21 minutes???
Spelling and grammer subject to change without notice.
Because Mars is further away than the Sun is.
Mars can be on the other side of the sun from us. Then the signal would take 21 min. Right now it isn’t, so I think the 10 minute value is correct.