Date: Year 1, Sur One, Sol 6 (1.1.6)
If you understand the reason humans created time zones on Earth, you will understand that we have the same need on Mars. On Mars, time zones are divided into 15° segments of longitude.
On Earth, the beginning point of all time zones is in Greenwich, England. It was referred to as Greenwich Mean Time (GMT) but is now replaced by Coordinated Universal Time (UTC). Every time zone on Earth is determined by how many time zones or hours it is from Greenwich. For example, Pacific Standard Time (PST) is currently eight hours behind UTC, so it is referred to as UTC -8.
Mars has been given a similar zone zero, like Earth’s UTC zone. It is located at the Airy Crater and that zone is known as Mars Coordinated Time (MTC). Our primary landing site on Mars is the Noctis Labyrinthus which is seven hours behind the Airy Crater or MTC -7.
As I am writing this post, it is 6:11 PM (18:11) PST, 8 January, 2016, on Earth. The time at our primary landing site on Mars is 8:33 AM (08:33) at what we are calling Noctis Standard Time (NST). The date is 6 Sur One, meaning it is the 6th day of the first month of Sur winter.
However, a day on Mars, (the time it takes the planet to make one revolution,) is 2.7% longer than an Earth day (about 40 minutes longer.) This means that at 6:11 PM PST tomorrow, it will NOT be 8:33 NST on Mars. In fact it will be 7:53 NST. To keep Mars on a 24 hour day scientists have devised a time system for Mars by making each second 2.7% longer than an Earth second.
If you are an astronaut on Mars, this is not an issue; however, if you’re a Mars scientist on Earth then you will experience a Mars ‘time creep’ where each Mars day pushes your Earth schedule 40 minutes forward each day.
As more of Mars becomes occupied by humans the time and day length differences will seem more commonplace; however, it can be confusing when someone says it will take 110 days to reach Mars because you have to know if that is Earth days, or Mars days.