Ramadan 2010 Calendar Astronomical Data


The Sun and the Moon follow courses (exactly) calculated (Al-Qur'an 55:5)

Due to adverse weather conditions in UK, it is not always possible to sight the New Moon (Hilal) from any one location within UK in each month. Therefore, past Ulamah (Muslim Scholars) have preferred to follow the nearby Muslim countries to UK for Moon Sighting news (e.g. Morocco). However, recent advancements in telecommunications technology has lead to the Moon Sighting news being received from many parts of the world, specially the Middle East, and since this news comes as much as two days before any possible sighting in UK (or nearby countries), Muslims in UK have been greatly confused as to which country to follow.

This confusion is repeated almost every year - leading to Ramadhan and Eids being celebrated over two or three days (instead of one day!) in UK.The motion of the Moon is very complex. The synodic month (or lunation) is the mean time from one new Moon (conjunction) to the next. The word synodic comes from the Greek word synodos or meeting, referring to the Moon’s conjunction with the Sun. Between 1000 BCE and 4000 CE it ranges from 29 days 6 hours and 26 minutes (29.27 days) to 29 days 20 hours 6 minutes (29.84 days) with a mean of 29 days 12 hours 44 minutes 3 seconds (29.530588853 days).

suni copy

Some sources describe an arithmetical (tabular) Islamic calendar. It is sometimes used for approximate conversions for civil purposes, but is not used for religious purposes by Sunnis or Twelver Shi‘ites (Ithna Asharia). However, it is common among Sevener Shi‘ites (Isma‘ili), including the Bohras (Musta’lis) and Nizaris (Isma‘ili Khojas, Aga Khanis).

It seems to have been designed to be closer to new Moon than to the first visibility of the lunar crescent, so it often runs a day or two ahead of the regular Islamic calendars. There are currently about one million Bohras and about 15 millions Nizaris, compared to over a billion Sunnis and close to a hundred million Twelver Shi‘ites. Both of these groups are today primarily Indian Muslim groups, but they trace their history from the Fatimid Caliphate that ruled Egypt from about 970 to 1171.

The calendar was put into practice by Imam al-Hakim (985–1021) and is therefore sometimes referred to as the Fatimid or misr (Egyptian) calendar. The calendar is sometimes attributed to the famous astronomer Al-Battani (850–929) and an alternative version to Ulugh Beg (1393–1449). It is also sometimes referred to as hisabi. It is possibly also used by the Qadianis (Ahmadiyyas), but they also seem to use a solar calendar.

The average lunar year is about 354 11/30 days, so you get a reasonable lunar calendar by using a cycle of 11 leap years (kasibah) with 355 days in a 30 year cycle. The odd numbered months have 30 days and the even numbered months have 29 days, except in a leap year when the 12th and final month has 30 days.

There are several versions for how to space out the 11 leap years. The most common rule is the one followed by the Nizaris Isma‘ili, which uses years 2, 5, 7, 10, 13, 16, 18, 21, 24, 26, 29, but some replace 16 by 15 and the Bohras replace 7 by 8, 18 by 19 and 26 by 27.


Moon is a convenient time keeper. Most ancient calendars started out as observational lunar calendars, with the month starting either with the first visibility of the crescent Moon, or with the full Moon. However, as their astronomical skills developed, most societies switched to starting the month at the computed time of the new Moon. In China, this change seems to have taken place in 621 CE .

When converting, it is important to remember that the Muslim day starts at sunset, so strictly speaking the Muslim month will usually start on the evening of the second day of the Chinese or Jewish calendar. However, the comparison with the Jewish calendar is complicated by the fact that the Jewish calendar uses mean values for the length of the month, so the first day of the Jewish calendar is not necessarily the exact day of the new Moon.

The day - One remnant of change from observational lunar calendars to computed lunar calendars is in the convention for the start of the day. The first visibility of the lunar crescent will occur in the West after sunset. For a calendar that starts the month with the first visibility of the lunar crescent it makes sense to start the day at sunset. However, if the month starts with the new Moon, it may be more natural to start the calendar day with sunrise or midnight.


Astronomers, however, are nocturnal, and may prefer to start the day at noon. Greenwich Mean Time (GMT) is actually measured from noon whereas Coordinated Universal Time (UTC) is measured from midnight. However, few use the noon measurement and most refer to GMT as if it were actually UTC.

Many people are confused by the acronym UTC for Coordinated Universal Time. In 1970 the Coordinated Universal Time system was devised by an international advisory group of technical experts within the International Telecommunication Union (ITU). The ITU felt it was best to designate a single abbreviation for use in all languages in order to minimize confusion. Since unanimous agreement could not be achieved on using either the English word order, CUT, or the French word order, TUC, the acronym UTC was chosen as a compromise.

When converting between calendars that start the day at different times, we will always match the main daylight parts of the days. So “today” means the Western or Chinese day that started at midnight, the Muslim day that started at sunset last night and the Indian day that started at sunrise this morning.


Our Observation and contribution for the correct dates will be for London - England as follows:- Ramadan 1431 AH: 10th August 2010. The astronomical New Moon phase starts on 9th Tuesday, August, 2010 at 6:44 Am London time. The New Moon Phase Ends on 10th August 2010 at 3:07 am London time.

The First Phase of the Moon Starts - Tuesday, 10th August, 2010 at 3:07 am London time.

First phase of the Moon will be not visible on this evening, the crescent is too thin to be visible to the naked eye.

Therefore the following day Wednesday, 11th August, 2010 is the 2nd Phase of the Moon which will be visible (Hilal). The second phase starts at 11:20 PM on 10th Tuesday night and ends on 11th August Wednesday, 2010 at 7:35 PM. First day of Ramadan will be 10th Tuesday and 11th Wednesday,  August  2010.

The 1st lunar day or ends at around 12° of solar separation, and the 2nd lunar day begins. The only part of this, that might be confusing is that the 30th lunar day (348 to 360°) is considered the Birth of New Moon day and the 15th lunar day (168 to 180°) is considered the Birth of Full Moon day.

In addition, the ecclesiastical Full Moon is not the astronomical Full Moon -- it is based on tables that do not take into account the full complexity of lunar motion. As a result, the date of an ecclesiastical Full Moon may differ from that of the true Full Moon. The ecclesiastical Full Moon is defined as the fourteenth day of a tabular lunation, where day 1 corresponds to the ecclesiastical New Moon.

The Moon Phase will be half on 16 August 2010 starts 6:36 AM and ends on 17 August 6:00 AM

The beginning point is the birth point and is the most certain point which can be forecast months and years ahead of time with the help of accurate astronomical calculations. Therefore, there is nothing wrong in accepting the 1st phase of the New Waxing Moon as the starting of the new months.

Full Moon

The full moon phases correspond to 13th, 14th and 15th month, which are reported in the Hadith as “Siyam Abyad” or “White Fasts”. As the moon moves further, the shape changes, until we see the “reverse crescent” at Fajr. Then it disappears completely, typically for one or two days until it reappears as the Hilaal and the cycle repeats.

The 13th, 14th and 15th of the bright half of the Full Moon will as follows:- From 21st August 2010

The 13th Phase starts on 21st August 10:07 AM

The 14th Phase starts on  22nd August 12:16 PM

The Full Moon Phase starts on 23rd August  2:37 PM

Full Moon Phase Ends on 24 August  5:03 PM - (Full Moon Completes and the dark half of the moon phase starts)

mphase1The Arabs went a step further and divided the 30-day month into 10 portions of three days each and assigned names to them.

Thus, for example, the middle portion (13th to 15th) is described as ayyam al bid (days of light) while the last one (27th to 30th ) is ayyam al mihaq (days of darkness), al-istitar (concealment) or as-sua'l (enquiry).

The moment of the Full Moon (al badr in Arabic), on the other hand, is midway between two successive conjugations when the three bodies again lie in a plane, but with the earth in the middle (a lunar eclipse can only occur at this moment).

Practically this moment (when the moon appears as a perfect luminous disc) occurs between the 13th and 15th of the lunar month that started with the correct sighting of the moon. The Arabic name for this period (ayyam al bid) is as a result of two phenomena unique to this period, that is, the moon is brightest and there is no total darkness during this period since there is an overlap between daylight and moonlight at dusk and dawn.

Caldwell and Laney of the South African Astronomical Observatory explain:
"Each new astronomical lunar month (lunation) begins at the moment when the center of the moon has the same celestial longitude as the center of the sun, from the perspective of the center of the earth, i.e. the moment when the moon "passes" the sun.

This is the moment of astronomical new moon, and it occurs at the same instant everywhere since it does not depend in any way on the viewer's perspective. At this time the moon is always invisible from the earth. When the moon first becomes visible again, observers see a young crescent moon" in some part of the world.

Lailat al Qadr

Lailat al Qadr 05 September 2010 (27 Ramadan). Laylat al-Qadr is the Night of Power when the first revelation had been given to Prophet Muhammad (PBUH) from the Angel Jibril. The Night of Power is better than a thousand months. Al-Qadr (Night of Power) - Surah 97: Verse 3

Any action done on this night such as reciting the Qur’an, remembering Allah, etc. is better than acting for one thousand months which do not contain the Night of Power. It has been recommended that, one of the odd numbered nights of the last ten days of Ramadan, i.e. from 29th August 2010 (21st, 23rd, 25th, 27th or 29th of the lunar phase) On these night Muslims can ask for forgiveness, reading Nawfaal, extra praying, etc.  Muslims will go into isolation and perform prayers. They will also remember the Itikaf that Prophet Muhammad (PBUH) performed when he received the first revelation, in cave Hira, 610CE.

Moon Phase will be half on 14 September 2010 starts at 5:38 PM and ends at 15 September 6:11 PM

The 1st lunar day or ends at around 12° of solar separation, and the 2nd lunar day begins.

The only part of this, that might be confusing is that the 30th lunar day (348 to 360°) is considered the Birth of New Moon day and the 15th lunar day (168 to 180°) is considered the Birth of Full Moon day.
Moon Rise Times - New Moon Always Rises at Sunrise.
First Quarter of Moon Rises at Noon. The Full Moon Rises at Sunset.
The Last Quarter Moon Rises at Midnight.
Moon Rise Takes Place about 48 Minutes Later Each day.

Eid ul-Fitr 1431 AH: The astronomical New Moon starts on 7th Tuesday, September, 2010, at 2:20 pm

The astronomical New Moon ends on 8th Wednesday, September, 2010, at 10:28 AM London time

The first phase, the first of Shawwal month starts on 8th Wednesday, September, 2010, at 10:28 AM

The first phase, of Shawwal month ends on 9th Thursday, September, 2010, at 6:37 AM London time, and the Second Phase of the Moon Starts, the moon is visible today.

Therefore, first day of Shawwal, i.e., Eid ul-Fitr is 8th Wednesday / 9th Thursday, September 2010.


The  AH and AJ Islamic day begins at Sunset. Commencing and Ending of Ramadan, Eid-ul-adhaa, Qurbani, the days of Hajj are all dependent on the Islamic months. In addition, the Zakat of wealth, also depends on the lunar calendar. The Iddat after Talaaq - specific period after divorce or death of the husband, age of puberty etc

Dr Jamal Badawi - He discusses various views and highlights the need for unity.

Dr Abdurazak Ebrahim Snr explains the same event, albeit in different words: For approximately fifteen hours on either side of the instant of conjugation, the moon is completely hidden from view. Full moon on the fourteenth day: First we need to explain what Full Moon is. Remember that as the moon revolves around the earth the latter revolves around the sun and, at a certain time, the three objects align, with the moon in the middle.

This moment, termed conjugation or the birth of the New Moon (a solar eclipse can only occur at this moment), marks the astronomical end of a lunar month and the beginning of another. The length of a lunar month, also called synodic period, is the period between two successive conjugations and is twenty-nine days, twelve hours and forty-four minutes (i.e., 29.53 days).

The major events in the lunar circle are summarized by Dr Ebrahim Snr: "Consequent to the first appearance of the lunar crescent on the western horizon after sunset the moon waxes (due to increased illumination) until (about) the fourteenth night when it appears as the Full Moon. After this the moon wanes (due to diminishing illumination) until it disappears over the eastern horizon before sunrise on the twenty-eighth day of the month."

Moonsighting Shaykh ul Islam Dr. Muhammad Tahir ul Qadri. Questions & Answers

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