Each day on Earth begins at midnight in Greenwich, England, where the prime meridian is located. Originally, the prime meridian’s purpose was to help ships at sea find their longitude and determine accurately their position on the globe.

American Samoa

Kiribati

The world is divided longitudinally into time zones, with each hour difference roughly 15 degrees apart. Due to some countries having half hour time zones, there are more than 24 times zones in the world. Most countries, especially the smaller ones, have only one time zone.

The last countries to ring in 2020 will be the tiny outlying island of the US, Baker, and Howland, which will enter the New Year at 5:30 IST on January 1.

The entire globe seems to be on the same day and date for one hour every day. It starts when the eastern edge of the UTC-11 time zone hits midnight. It ends when the eastern edge of the next time zone, the IDL (UTC±12), hits midnight. At that time a new day begins to unreel.

When meridian -165 reaches 12 midnight the whole earth experiences the same date for another 1 hour. When the IDL experiences midnight, a thin sliver of earth’s surface making up to 7.5° of the meridians east of IDL experience new date while the rest of the earth is on previous date.

Generalized Time Zones in United States

Current Local Times Around the World

six

Since Texas (TX) and Chicago, Illinois currently have equivalent time zones, you can call someone during your normal hours and it will be the same time in Chicago, IL as it is in Texas. This will be between 7AM – 11PM their time, since Chicago, Illinois is in the same time zone as Texas (TX).