We must be familiar when we hear the term Greenwich Mean Time (GMT). GMT is a system of setting the time difference in world countries based on geographic location. But did you know that GMT is deprecated?
GMT has been replaced with UTC (Universal Time Coordinated). GMT itself has been used since 1884. GMT is an international time reference based on the sundial in the city of Greenwich, England.
Reporting from the official website of the Indonesian Institute of Sciences (LIPI), it was explained that since 1972 the sundial was no longer used as a benchmark for time.
Time benchmarks were replaced with atomic clocks synchronized with sundials.
The atomic clock was chosen because it has a more stable time calculation. The change from sundial to atomic clock is a sign that GMT is no longer a reference for international time.
The international time reference has been replaced by UTC which uses atomic clocks as an international standard of uniformity of seconds.
Reporting from the official Encyclopedia Britannica page, it is explained that although GMT is no longer used as a reference for international time, GMT is still used to represent civil time in the UK.
Time Sharing in Indonesia
Based on the UTC format, the territory of Indonesia is divided into three time zones, namely UTC +7 (Western Indonesian Time), UTC +8 (Central Indonesian Time), and UTC +9 (Eastern Indonesian Time).
UTC +7 means that the western part of Indonesia is seven hours ahead of UTC. For example, 00.00 UTC is equivalent to 07.00 WIB.
Time division in some countries
Here are some examples of using the UTC format to show the time in some countries:
Paris, France UTC +1
Madrid, Spain UTC +1
London, UK UTC +00 (meaning that the hours in London, England are the same as UTC hours. If the UTC clock shows 10.00, then in London, England it also shows 10.00).
Berlin, Germany UTC +1 Germany
Moscow, Russia UTC +3
Tokyo, Japan UTC +9
Beijing, China UTC +8
Seoul, South Korea UTC +9
Riyadh, Saudi Arabia UTC +3
Doha, Qatar UTC +3
New Delhi, India UTC +5.30
Ottawa, Canada UTC -5 (for example, 12.00 UTC is equivalent to 07.00 in Ottawa, Canada).
Buenos Aires, Argentina UTC -3
Washington DC, United States UTC -5
So, if you want to see the time of countries in the world, then your benchmark is UTC hours.
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If you are still confused, you can visit the official Time and Date page to find out the time of the countries in the world.
Kita pasti tidak asing ketika mendengar istilah Greenwich Mean Time (GMT). GMT merupakan sistem pengaturan perbedaan waktu di negara-negara dunia berdasarkan letak geografis. Tapi tahukah kamu bahwa GMT sudah tidak digunakan lagi?
GMT sudah digantikan dengan UTC (Universal Time Coordinated). GMT sendiri sudah digunakan sejak tahun 1884. GMT merupakan rujukan waktu internasional yang didasarkan pada jam matahari di kota Greenwich, Inggris.
Dilansir dari laman resmi Lembaga Ilmu Pengetahuan Indonesia (LIPI), dijelaskan bahwa sejak tahun 1972 jam matahari sudah tidak lagi digunakan sebagai patokan waktu.
Patokan waktu digantikan dengan jam atom yang disinkronkan dengan jam matahari.
Jam atom dipilih karena memiliki perhitungan waktu lebih stabil. Pergantian dari jam matahari ke jam atom menjadi tanda bahwa GMT bukan lagi rujukan waktu internasional.
Rujukan waktu internasional digantikan dengan UTC yang menggunakan jam atom sebagai patokan keseragaman detik secara internasional.
Dilansir dari laman resmi Encyclopedia Britannica, dijelaskan bahwa meskipun GMT tidak lagi digunakan sebagai rujukan waktu internasional, GMT masih tetap digunakan untuk mewakili waktu sipil di Inggris.
Pembagian Waktu di Indonesia
Berdasarkan format UTC, wilayah Indonesia terbagi dalam tiga zona waktu, yaitu UTC +7 (Waktu Indonesia Bagian Barat), UTC +8 (Waktu Indonesia Bagian Tengah), dan UTC +9 (Waktu Indonesia Bagian Timur).
UTC +7 memiliki arti bahwa wilayah Indonesia bagian barat memiliki selisih waktu tujuh jam lebih cepat dari UTC. Misalnya, jam 00.00 UTC setara dengan jam 07.00 WIB.
Pembagian waktu di beberapa negara
Berikut beberapa contoh penggunaan format UTC untuk menunjukkan waktu di beberapa negara:
Paris, Perancis UTC +1
Madrid, Spanyol UTC +1
London, Inggris UTC +00 (artinya jam di London, Inggris sama dengan jam UTC. Apabila jam UTC menunjukkan angka 10.00, maka di London, Inggris juga menunjukkan angka 10.00).
Berlin, Jerman UTC +1 Jerman
Moscow, Rusia UTC +3
Tokyo, Jepang UTC +9
Beijing, China UTC +8
Seoul, Korea Selatan UTC +9
Riyadh, Saudi Arabia UTC +3
Doha, Qatar UTC +3
New Delhi, India UTC +5.30
Ottawa, Kanada UTC -5 (misalnya, jam 12.00 UTC setara dengan jam 07.00 di Ottawa, Kanada).
Buenos Aires, Argentina UTC -3
Washington DC, Amerika Serikat UTC -5
Jadi, apabila kalian ingin melihat waktu negara-negara di dunia, maka patokan kalian adalah jam UTC.
Jika kalian masih bingung, kalian bisa mengunjungi laman resmi Time and Date untuk mengetahui waktu negara-negara di dunia.