The time difference between two locations is the amount of time that passes between the same moment in each location. The most obvious example of this is the difference between two cities in different time zones. For example, the time difference between New York and London is five hours. This means that when it is noon in New York, it is 5pm in London.
The time difference between two locations can also be caused by Daylight Saving Time (DST). DST is when a region changes its clocks forward or backward by an hour in order to make better use of daylight. This means that the time difference between two regions can change depending on the time of year. For example, the time difference between New York and London is four hours during the summer months when DST is in effect.
The time difference between two locations can also be caused by the International Date Line (IDL). The IDL is an imaginary line located between the Pacific and Indian Oceans. When crossing the IDL, the date changes by one day. This means that the time difference between two locations can be 24 hours. For example, the time difference between New York and Tokyo is 14 hours during the summer months, but it is 15 hours during the winter months.
Overall, the time difference between two locations is determined by the time zone, Daylight Saving Time, and the International Date Line.