The International Date Line corresponds to 180 degrees longitude on the earth. If you imagine the Greenwich Meridian as a circle all the way round the globe (through Greenwich and both poles) the date line is the part of the circle on the "other side" from Greenwich. It is very difficult to follow what is happening at the date line, and if it doesn't take you a long time, you are very bright. The line is right in the center of its time zone. If you are standing right to the east of the date line (to the right as you would see it on a map) and your friend is a few feet away from you, standing just to the west of the line, then your friend will always be exactly one day ahead of you. On your side, it might be 10 am Tuesday October 9. For your friend, it will be 10 am Wednesday, October 10. At the stroke of midnight, you both go to the first hour of the next day. That's the part I had trouble wrapping my brain around. One trick to understanding the date line is to remember that there is another "line" that separates 2 adjacent days-- Midnight. Of course, midnight moves, while the date line is fixed. There are some nations (including the US) that are affected by the placement of the date line, and there are no laws governing its actual location. However, virtually everyone knows that there is a need for such a dividing line. There are also some island nations in the Pacific that are affected by the date line, and all of these affected nations have "defined" the date line to be farther to their east or to their west than the originally defined 180 degrees longitude, so that all of their territory could be operating on the same calendar day. As a result of the change made by the island nation of Kiribati, Caroline Island was the first point on the globe to enter the year 2000.
The dateline is a line at the beginning of a news article indicating the date and location of the story's origination. It provides readers with important context about where and when the events being reported on took place.
I am assuming you are asking about the International Date Line. It is the imaginary line opposite the Greenwich Meridian, and it is located at 180 degrees longitude. It is the line chosen to represent one of the boundaries between the two different days that are unfolding at any given time along the surface of the earth. See link for more details.
Although it sounds like a date such as month day and year, the dateline is actually in the first line of an article and is the location where the reporter is writing from.
For example: "LOS ANGELES - A woman gave birth to eight babies today."
In this example, the "dateline" is Los Angeles. Datelines are most often written in all capitals.
Although some newspapers don't put them on because of the town/city's importance. Like say for example that it might be just a small town(like a town or city with a low population). But if it was somewhere like Los Angeles then they would most likely include that in the dateline.
Dateline London was created in 1996.
Sunday
The duration of Dateline Diamonds is 1.22 hours.
The duration of Dateline London is 1800.0 seconds.
The duration of Dateline Philippines is 3600.0 seconds.
Dateline Diamonds was created on 1966-04-03.
Dateline NBC was created on 1992-03-31.
Dateline Philippines was created on 1996-07-10.
International Dateline Hotel was created in 1966.
The dateline stated the location and date of the news story.
The International Date Line passes through the Pacific Ocean. It is an imaginary line that runs from the North Pole to the South Pole, mostly along the 180° longitude line.
Dateline - 1999 is rated/received certificates of: New Zealand:PG