It is an Islamic tradition (Sunnah) for Muslims to look for the crescent moon (Hilal) on the 29th of the lunar month, and if it is not sighted, then it must be seen on the 30th (in a clear sky).
This is usually the case in all equatorial countries (i.e., in the vast majority of the Muslim countries) and it was also true in the UK for the past 15 years (since 2008) we have been doing moon sightings.
However, there is a special phenomenon known as the Major Lunar Standstills which causes the moon in high latitude countries like the UK to be at a very low altitude on the 29th and 30th, such that it may not be seen in those years, e.g., 2025 (2023-2027), even in clear skies.
This low altitude happens for a few months during the winter (Sep-Dec/Jan), and then it becomes high altitude in the spring (Feb-May), which balances out the total number of 29 and 30-day months.
The above Major Lunar Standstills happen once every 18.6 years for a few years, and since it is the first time in (the history of) our UK moon sighting experience, it is necessary to look for the moon over 3 days a month for data collection.
The question arises, is it permissible to look for the moon on multiple days? This question is better answered by considering the following verse of the Quran: وَالْقَمَرَ قَدَّرْنَاهُ مَنَازِلَ حَتَّىٰ عَادَ كَالْعُرْجُونِ الْقَدِيمِ
“And [for] the moon, We have measured for it mansions (to traverse) till it returns like the old dried curved date stalk”, Quran (36:39)
It is clear from the Tafsir Jalalayn of the above verse that the moon goes through visible phases until it disappears and enters the invisible phase (Mahaq). The Arabs have a name for each set of three nights in a month, according to the phases of the moon (Ghurar to Mahaq), as stated in the Tafsir Ibn Kathir. Therefore, it is not wrong to look for any number of the visible or invisible phases of the moon, especially if it can help establish a more accurate predicted crescent visibility (Imkan Al-Ruyat) calendar, InshaAllah.
Therefore, we would like to request all UK Muslims to report their moon sightings to our Moon Sighting UK (ICOUK) website on the 29th and the next 2-days of the month (based on the UK count) during the UK winter months, e.g., on the 15th Sep (29th Safar), 16th Sep (30th Safar) and 17th Sep 2023 (1st Rabi-I 1445), InshaAllah. JazakAllahu Khaira!
Checked by: Maulana Abdullah Ahmed (9/2023)
Related: Importance of Moon Sighting | Why look for the moon after 29th date? | Major Lunar Standstills Istiftaa | First day's moon on UK horizon