International Date Line
International Date Line West (GMT-12:00)
The importance of international date line (west) is that if you cross the international date line then the date will change. For example if you travel across the international date line from East to West then your date will change to the next date. Similarly if you cross the international date line from west to east, then you will go back to yesterday's date. MatsClock-gmt-1350 displays the time 12 hours less the Greenwich Mean Time or Coordinated Universal Time. Crossing the international date line is like time travel where you cannot actually travel back and forth in time but certainly travel from today to tomorrow's date or go back from today to yesterday's date. You can also say that when it is mid night at the international date line, it will be mid day at Greenwich Meridian. Exactly half a day or 12 hours difference between the time at places on the greenwich meridian and the places on the international date line.
Country Standard Time GMT-1200
There are a few countries that uses GMT-12:00 hours as their country standard time like the Baker Islands and Howland Islands which are the United States Minor Outlying Islands. MatsClock 1350 displays the time offset of GMT-12:00 hours always.
Why is GMT-12:00 hours is called the International Date LIne?
GMT-12:00 or a time offset of GMT minus 12 hours is also called the international date line. This is an imaginary line on the surface of the earth. The International Date Line was established in 1884 during the Internataional Meridian Conference. The International Date Line runs from the north pole till the south pole and it demarcates one calendar day from the next. It passes mostly over the pacific ocean at about the 180 degree longitude but becomes irregular at places and island group so that a single country does not have two different dates on either side of the International Date Line. So if you travel from the International Date Line crossing it from the east to west then you have to add one day and crossing the International Date Line from west east you subtract one day from your calendar. The date actually changes on the International Date Line in the midnight. But since some countries use daylight saving times, often there are three dates being used in the world during a two hour period between Greenwich Mean Time of 10:00 pm and 11:59 pm. This is true. The world has three different dates every day 2 hours close to the midnight at International Date Line.
New Date Country - International Date Line GMT-1200
The first major city that observes a new date and even a new year on its clock is Aukland, New Zealand. The other areas who sea first daylight of a new day will vary by seasons. The south pole witnesses the first daylight in midnight sun on 01 Jul and McMurdo Station in Antartica as both uses GMT-13:00 Hours time offset. The other is a large part of Chukchi Peninsula using UTC+12 hours.