Topic: Lunar Calendar and Standard Time was developed for Lunar residents

[Software Santa]

The Lunar Calendar and Standard Time was developed for the use of (any future) Lunar residents to keep LOCAL Time!

               http://lunarclock.org/service/flash/lstclocka.swf
The triangles show seconds, minutes and hours.
The circles show cycles, and the boxes show Lunar days.
The large number in the middle is the current Lunar year.

LunarClock.org is a non-profit organization. Our mission is to develop and promote the Lunar Calendar and Standard Time, or shorter just Lunar Standard Time (or even shorter, just LST).

What?
The Lunar Calendar and Standard Time is just that, a calendar and time reckoning that is suitable for those one day living on the Moon. The LST was originally created by Rudolph N.J. Draaisma and is now maintained and developed by LunarClock.org.

Why?
What's the point of Lunar Standard Time? Well, it is pretty clear that the Moon will be colonized sooner or later - actually probably sooner than you might think (take look at these initiatives). When that happens, the people living there will find it strange to live by a clock that is based on conditions on Earth. It's a safe bet to assume that some sort of new way of denoting time will emerge on the Moon. This new calendar would be based on Moon conditions. And so, we propose the Lunar Calendar and Standard Time.

The Lunar year consists of twelve days, named after the first men who walked on the Moon. Each day is divided into 30 cycles of time, with each cycle being divided into 24 moon-hours. Each moon-hour then has 60 moon-minutes, which in turn of course are made up of 60 moon-seconds each.

The standard notation is: Year-Day-Cycle ∇ Hour:Minute:Second

45-08-23 ∇ 02:56:47  Lunar Standard Time (LST)

This feels similar to what we have here on Earth, does it not? That is the point. It feels similar, but there are differences.

Conditions on the Moon are somewhat different compared to the Earth. For one thing, you have about 15 days of continuous daylight (and then 15 days of total darkness). So, a "day" on the Moon, would correspond to about 29.5 Earth-days. About a month. And this is why we have months! You can see it in the sky, once every 29 days or so, you have a full moon, which is "noon" on the center of the disk. This is also called the synodic month.

So, on the Moon, a day, counting from noon to noon, lasts about 29.27 to 29.83 Earth days. It is not a constant. The mean value, roughly 29.530589, is not a constant either! Over time it will be longer. However, this will not be a problem in the near future (your grandchildren might have to add a leap second or two though) .

This means that we will have to fit 30 moon cycles into 29.53 or so Earth days, while keeping the same type of 24 hour clock that we have all come to know and love. The solution is to simply define the moon-second as 29.530589/30, and the rest follows. Go here for Lunar Standard Time definitions.

Neil Armstrong set foot on the Moon surface on July 21th 1969 at 02:56:15 UT, and this is the obvious choice for a point in time for the calendar to start. So, this is Year 1, day 1 cycle 1, 00:00:00

http://lunarclock.org