2017 June Solstice Happens Tuesday, June 20, or Wednesday, June 21

Summary: The 2017 June solstice, which occurs everywhere at the same time, happens Tuesday, June 20, or Wednesday, June 21, according to local time zones.

Earth at instant of 2017 June solstice, Wednesday, June 21, at 4:24 a.m. Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Domain, via Fourmilab Switzerland

The 2017 June solstice, which actually occurs as an astronomical season opener everywhere on Earth at the same time, happens Tuesday, June 20, or Wednesday, June 21, according to local time zones.

Coordinated Universal Time (UTC), the world’s official time standard, sets the astronomical event at 4:24 a.m., Wednesday, June 21. Conversion of the 2017 June solstice to local time accounts for date variations for the astronomical event. The earliest date for the astronomical event is Tuesday, June 20. The latest date of Wednesday, June 21, agrees with Coordinated Universal Time, although times may vary.

The highest time zone is 14 hours ahead of Coordinated Universal Time and claims Wednesday, June 21, as date of occurrence for the 2017 June solstice. The 14-hour offset is expressed as UTC + 14. The Central Pacific raised coral atoll of Kiritimati falls within the Line Islands Time Zone (LINT), which is 14 hours ahead of Coordinated Universal Time. Also known as Christmas Island, Kiritimati places the astronomical event at 6:24 p.m. LINT, Wednesday, June 21, 2017. Lying just north of the equator, Kiritimati observes the June solstice as a summer solstice.

Across the equator, at the 14th parallel south, Pago Pago, Tutuila, places the astronomical event one day earlier. Pago Pago lags 11 hours behind Coordinated Universal Time. The lag is expressed as UTC – 11. For the territorial capital of the U.S. unincorporated Territory of American Samoa, the June solstice happens Tuesday, June 20, at 5:25 p.m. Samoa Standard Time (SST).

As one of only two U.S. possessions in the Southern Hemisphere, American Samoa knows the June solstice as a winter solstice. Jarvis Island, the other unincorporated, unorganized U.S. territory, lies northeast of American Samoa, at a distance of 22 nautical miles (40.74 kilometers; 25.31 miles) south of the equator. The U.S. Fish and Wildlife Service (USFWS) and the National Oceanic and Atmospheric Administration (NOAA) administer the small, unoccupied coral island, with a diminutive area of 4.5 square kilometers (1.73 square miles), as part of the Pacific Remote Islands Marine National Monument.

Elsewhere in the Pacific Ocean, the United States’ two youngest states, Alaska and Hawaii, experience the June solstice also on Tuesday, June 20. Residing in the North Hemisphere, both states know the June solstice as a summer solstice.

Alaska mostly falls within the Alaska Time Zone. On Sunday, March 12, Alaska Daylight Savings Time (AKDT) takes over from Alaska Standard Time (AKST). The astronomical event mostly happens in Alaska at 8:24 p.m. AKDT.

The portion of the Aleutian Islands located west of 169.30 west longitude falls within the Hawaii-Aleutian Time Zone. Located at 176.636 degrees west longitude, the Aleutian Island of Adak falls within the Hawaii-Aleutian Time Zone and also observes daylight savings. With daylight savings in effect, Adak Island experiences the 2017 summer solstice Tuesday, June 20, at 7:24 p.m. Hawaii-Aleutian Daylight Savings Time (HADT).

Far south of Alaska, the state of Hawaii also falls within the Hawaii-Aleutian Time Zone. Hawaii does not observe daylight savings time. For the Aloha State, the 2017 summer solstice happens one hour earlier than in the time zone’s northern reaches. Hawaii’s 2017 summer solstice takes place Tuesday, June 20, at 6:24 p.m. Hawaii-Aleutian Standard Time (HAST).

The coasts of continental United States and Canada claim both dates for the June solstice. The Canadian and U.S. west coast place the 2017 summer solstice at 9:24 p.m. local time, Tuesday, June 20. Meanwhile, across the North American continent, Halifax, Nova Scotia, on Canada’s east coast, observes the astronomical event Wednesday, June 21, at 1:24 a.m. Atlantic Daylight Time (ADT). On the U.S. east coast, the nation’s capital, Washington, DC, logs the 2017 summer solstice at 12:24 a.m. Eastern Daylight Time (EDT), Wednesday, June 21.

Across the Atlantic Ocean, the southwestern European capital of Lisbon, Portugal, notes the 2017 summer solstice on Wednesday, June 21, at 5:24 a.m. Western European Summer Time (WEST). To the east, across Eurasia, the Russian Far East’s Pacific coast province of Primorsky Krai welcomes the 2017 summer solstice Wednesday, June 21, at 2:24 p.m. Vladivostok Time (VLAT).

In the Southern Hemisphere, Australia’s island state of Tasmania logs the June solstice as a winter solstice that happens Wednesday, June 21, at 2:24 p.m. Australian Eastern Standard Time (AEST). The South Atlantic coastal city of Cape Town observes South Africa’s 2017 winter solstice on Wednesday, June 21, at 6:24 a.m. South Africa Standard Time (SAST). Westward across the South Atlantic Ocean, Punta Arenas on the Pacific side of Chile’s southernmost region of Magallanes and Chilean Antarctica, marks southern South America’s 2017 winter solstice on Wednesday, June 21, at 1:24 a.m. Chile Standard Time (CLT).

The takeaway for the 2017 June solstice is that the astronomical event ushering in northern summer and southern winter happens Tuesday, June 20, or Wednesday, June 21, according to the world’s local time zones.

Earth at instant of 2017 June solstice, Wednesday, June 21, at 4:24 a.m. Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Domain, via Fourmilab Switzerland

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Earth at instant of 2017 June solstice, Wednesday, June 21, at 4:24 a.m. Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Domain, via Fourmilab Switzerland @ https://www.fourmilab.ch/cgi-bin/Earth

Earth at instant of 2017 June solstice, Wednesday, June 21, at 4:24 a.m. Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Domain, via Fourmilab Switzerland @ https://www.fourmilab.ch/cgi-bin/Earth

For further information:

“11 Things About the June Solstice.” Time And Date > Sun & Moon.
Available @ https://www.timeanddate.com/astronomy/facts-about-june-solstice.html

Byrd, Deborah. “Things to Notice at the June Solstice.” EarthSky > Tonight. June 20, 2016.
Available @ http://earthsky.org/tonight/solstice-brings-northernmost-sunset

“Event in UTC on Wednesday, June 21, 2017 at 4:24:00 a.m.” Time and Date > Time Zones > World Clock > Event Time Announcer.
Available @ https://www.timeanddate.com/worldclock/fixedtime.html?p1=1440&iso=20170621T0424&low=4

“HADT - Hawaii-Aleutian Daylight Time (Daylight Savings Time).” Time And Date > Time Zones > Abbreviations.
Available @ https://www.timeanddate.com/time/zones/hadt

Marriner, Derdriu. “2016 June Solstice Signals Summer Start But Also Begins Summer End.” Earth and Space News. Wednesday, June 15, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/06/2016-june-solstice-signals-summer-start.html

Marriner, Derdriu. “Full Strawberry Blue Moon Seasonally Welcomes 2016 June Solstice.” Earth and Space News. Wednesday, June 8, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/06/full-strawberry-blue-moon-seasonally.html

Marriner, Derdriu. “Martian New Year and Summer Solstice 2015: Happy New Year From Mars.” Earth and Space News. Saturday, June 20, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/06/martian-new-year-and-summer-solstice.html

Marriner, Derdriu. “Two Weeks After 2016 June Solstice Earth Reaches 2016 Aphelion.” Earth and Space News. Wednesday, June 29, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/06/two-weeks-after-2016-june-solstice.html