This includes the Chatham Islands, which is around 800 km east of New Zealand’s South Island. They are populated by around 720 people.

This time zone is used by the island nations of New Zealand, Samoa, and Tonga.
It only exists in a the southern hemisphere.

This timezone includes parts of Russia (Kamchatka), the islands of Wallis and Futuna, Tuvalu, Wake Islands, Marshall Islands, Gilbert Islands, and Fiji.

This Time Zone includes the Eastern Side of Australia which houses the Jervis Bay Territory, most of New South Wales, and the cities of Tasmania and Victoria.
It also includes most of the Autonomous Region of Bougainville in Papua New Guinea, and parts of Russia.

This covers parts of Australia including Broken Hill in New South Wales.

It does appear this time zone is Standard Time during the Southern Hemisphere Summer (which includes New Years Eve and Day). This includes parts of Australia, Russia, and possibly some bases in Antartica. 
We could use some clarification on the UTC+10 time zone during the New Year transition.

Includes parts of Australia including Darwin and Alice Springs.

This time zone covers Japan, Korea, parts of Northeast China, Western Australia, Federated States of Micronesia, parts of Russia, parts of Papua New Guinea. 

This time zone includes parts of Western Australia and Southern Australia.

This is the most populous time zone in the world. It includes the entire country of China, parts of Russia (Irkutsk), Mongolia, Hong Kong, Singapore, Malaysia, and parts of Indonesia.

Parts of Russia, the Western Part of Mongolia, all of Cambodia, Laos, Thailand, Vietnam, and parts of Indonesia.
Also, Christmas Island and some bases in Antarctica.

Includes Myanmar.
Also Coco Island and Cocos Islands.

Bangladesh, Bhutan, Kyrgyzstan, Russia (Omsk Oblast), and Chagos Archipelago.

This time zone is exclusive to Nepal.

India and Sri  Lanka.

Includes the countries of Kazakhstan, Tajikistan, turkmenistan, Uzbekistan, Maldives, Pakistan, along with parts of Russia, France, and Australia.

Afganistan. 

Russia – Samara Time, Armenia, Azerbaijan, Georgia (mostly), Oman, UAE

Iran

Bahrain, Iraq, Jordan, Kuwait, Qatar, Syria, Yemen, Saudi Arabia, Comoros, Djibouti, Eritrea, Ethiopia, Kenya, Tanzania, Uganda

Botswana, Burundi, Eswatini, Lesotho, Libya, Malawi, Namibia, Rwanda, South Africa, South Sudan, Sudan, Zambia, Zimbabwe, Russia (Kaliningrad Oblast)

Albania, Andorra, Austria, Belgium, Bosnia and Herzegovina, Croatia, Czech Republic, Denmark, France, Germany, Hungary, italy, Kosovo, Liechtenstein, Lixembourg, Malta, Monaco, Montenegro, Netherlands, North Macedonia, Norway (Svalbard, Jan Mayen), Poland, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden (Gotland), Switzerland, United Kingdom (Gibralar), Vatican City

Ireland, Portugal, United Kingdom, Channel Islands, Isle of Man, Faroe Islands, Canary Islands, Burkina Faso, Ivory Cost, The Gambia, Ghana, Guinea, Liberia, Mali, Mauritania, Senegal, Sierra Leone, Togo, Greenland (Danmarkshavn, Station Nord), Iceland

Cape Verde, East Greeland, Azores Islands

Most of Greeland, parts of Brazil, UK governed South Georgia and the South Sandwich Islands.

Canada (New Brunswick, Newfoundland, Labrador (mostly), a small part of Greenland (Pituffik), Bermuda, Argentina, most of Brazil, Paraguay, Siriname, Falkland Islands, Uruguay.

Canada (Newfoundland and Labrador (partly))

Canada (New Brunswick, Newfoundland and Labrador, Prince Edward Island), Greenland (Pituffik, Qaanaaq), Bolivia, West Brazil, Guyana, Venezuela, Antigua and Barbuda, Barbados, Dominica, Dominican Republic, Trinidad and Tobago, United States (Puerto Rico, United States Virgin Islands)

Canada (Ontario, Quebec), United States (Delaware, District of Columbia, Florida, Georgia, Indiana, Kentucky, Maine, Maryland, Michigan, Connecticut, Massachusetts, Maine, New Hampshire, Rhode Island, Vermont, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia), Bahamas, Cuba, Haiti, Navassa Island, Colombia, Ecuador, Peru, Jamaica, Mexico (Quintana Roo), Panama

Canada (Manitoba, Nunavut, Ontario) Mexico (Chihuahua, Nuevo Leon, Tamaulipas), United States (Alabama, Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Minnesota, Mississippi, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Texas, Wisconsin), Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Easter Island 

Canada (Alberta, British Columbia, Northwest Territories), United States (Azrizona, Colorado, Idaho, Kansas, Montana, Nebraska, Nebada, New Mexico, Utah, Wyoming), Mexico (Baja California Sur, Sinaloa, Sonora)

Canada (British Columbia (parts)), Mexico (Baja California), United States (California, Nevada, Oregon, Washington, Clipperton Island, Pitcairn Islands

United States (Alaska), Gambier Islands

French Polynesia

Cook Islands, United States (Hawaii, Johnston Atoll)

Niue, American Samoa

Baker Island, Howland Island