The Muslim celebration of Eid al-Fitr – the festival of breaking the fast – will begin with the sighting of this month’s young moon in the west after sunset. Eid al-Fitr marks the end of the holy month of Ramadan. It falls on (or near?) the same day of the Islamic calendar, a lunar calendar, but the date varies widely from year to year on the more commonly used Gregorian calendar, a solar calendar. The date of Eid al-Fitr also typically varies from country to country, depending on whether the moon has been sighted. Martin Bentz wrote asking about the date of Eid this year. He said:
The night the crescent moon is seen signifies the next day is the Eid Al Fitr or the the Celebration of Breaking Fast. The Eid starts with a communal prayer around 7 or 8 a.m., usually in an open area (a field or stadium) to give thanks to God for making in through the Ramadan fast. All Muslims can then eat during the day and families get together after prayers to celebrate.
The date of Eid is set by Muslim clerics. My apologies to the Muslim community if I’m wrong in this post about any details regarding Eid. My expertise isn’t Eid by any means, but instead young moon sightings. In 2018, much of the world will see the young moon on June 14, although – for countries just west of the International Date Line, for example, countries in far eastern Asia – the young moon sighting will likely be June 15.
Every month, the date of a young moon sighting depends on multiple factors, but mainly it depends on the date and time of new moon. This month’s new moon falls on June 13 at 19:43 UTC (Coordinated Universal Time). Note that UTC used to be called GMT (Greenwich Mean Time). Nowadays UTC, not GMT, is the time standard. Translate UTC to your time.
Please look below for more about expected young moon sightings this month, and Eid in 2018.
When a new moon happens close to the moon’s perigee – or closest point to Earth for the month – that factor favors an earlier young moon sighting for everyone. Additionally, the moon’s whereabouts relative to the ecliptic – or plane in space created by the Earth and sun – is a factor. The June 2018 new moon is quite close to the ecliptic. In years when the new moon is significantly north of the ecliptic, the young moon sighting favors the Northern Hemisphere; or in years when the new moon is significantly south of the ecliptic, the young moon sighting favors the Southern Hemisphere.
The time of year makes a difference, too. The least favorable time is late summer/early autumn (August, September, October for the Northern Hemisphere; February, March, April for the Southern Hemisphere).
In June, from most places in the world, it’s possible to see a young moon in the west after sunset 24 hours or more after new moon. Astronomers say such a moon is 24 hours old. It’s more difficult to see a moon less than 24 hours old. Such a moon shows us less of its lighted face, and it’s closer to the sun, more deeply buried in twilight after sunset.
A reliable record for young moon sightings was set by writer, photographer, and naturalist Stephen James O’Meara in May 1990. He saw a young crescent with the unaided eye 15 hours and 32 minutes after new moon. Click here to read more about the youngest moons it’s possible to see. To my knowledge, it’s not possible to see a moon less than 15 hours and 32 minutes old, although there are unsubstantiated reports of such sightings. I saw an 18-hour-old moon once, but surely would not have seen it if I had not been looking in the purest of skies, from a high place. Even under those ideal conditions, my 18-hour-old moon appeared extremely ghostly, but of course extremely beautiful.
North and South America will see the young moon on June 14. New moon is June 13 at 19:43 UTC, which translates to 4:43 p.m. BRT in Rio de Janeiro, Brazil; 3:43 p.m. EDT in New York City; and 12:43 p.m. PDT in San Francisco. Thus the moon will not be visible on June 13. But, from all of those places – and west of all of those places to the International Date Line – the moon will be greater than 24 hours old on June 14. It will be visible – albeit low in the sky, hidden by any low-lying clouds, trees or tall buildings – on June 14.
London will see the young moon on June 14 (in theory). New moon on June 13 at 19:43 UTC translates to 8:43 p.m. BST in London, England. In London on June 14, the sun sets at 9:19 p.m. BST, so the moon will be 23-and-one-half hours old at the time of sunset in London. It’ll be old enough to see, in theory, although – at London’s high latitude – the late summertime twilight will interfere. Are you beginning to see why these young moon sightings can be so complicated? Just as Nature expresses itself slightly differently from place to place on Earth, so there are little (or big) differences in the sky, as seen from around the globe. Yet it’s all just one Nature, as we know.
Mecca will see the young moon on June 14. New moon on June 13 at 19:43 UTC translates to 10:43 p.m. AST in Mecca, Saudi Arabia, Islam’s holiest city. The sun sets in Mecca at 7:04 AST on June 14. The moon will be about 21-and-one-half hours old at that June 14 sunset, still possible to see (although difficult). And Mecca is much farther south than London, and so its twilights will be shorter than those in London. Hence, darkness will fall more swiftly after sunset, making the young moon easier to see.
Thus, for Mecca and points west – to the International Date Line – the young moon will be possible to see on June 14. Going east from the longitude of Mecca – into time zones in South and East Asia – the prospects for young moon sighting on June 14 grow dimmer.
India may or may not see the moon on June 14. Mumbai – India’s largest city – on the west coast of India will have a better chance of seeing the young moon than, for example, than any city on the east coast of India. But I don’t know if the clerics will decide the date of Eid for India as a whole, or city by city. If anyone knows, please tell me in the comments below.
Far east Asia will likely see the moon on June 15. Jakarta, Indonesia, is 7 hours ahead of UTC. So the new moon in Jakarta came not on June 13, but on June 14 at 2:43 a.m. Thus at sunset in Jakarta on June 14 – which happens at 5:46 p.m. that day – the moon would be only 15 hours old, younger than Stephen O’Meara’s record sighting. In Singapore, which is 8 hours ahead of UTC, the moon on June 14 will be even younger and surely impossible to see.
The chart below is set for the middle of North America. The moon will be offset from other places around the globe. However, you might enjoy this chart – if watching for young moons this week – because it identifies the bright planet that will be near this young moon in the west after sunset. That planet is Venus. Mercury is also in the west after sunset, but closer to the horizon, not as bright as Venus, and thus harder to spot.
Bottom line: A day – or two – after this month’s new moon, Muslims will celebrate Eid al-Fitr, the “festival of breaking the fast.” Its date is variable and begins with a young moon sighting. When to expect that sighting in 2018, here.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.