Study how Prayer time is calculated

[iqfareez]

This study is similar to #178, except, this thread only focus on the prayer times.

There are various methods in calculating the prayer times. Different countries may use different methods depending on their respective authority.

Even same countries, may have slightly different calculation method involved, resulting in slightly offset prayer time. Someone noticed it, and I also tweeted about it a while ago.

The time below is taken from Google (just search prayer times <your location> and Jakim E-Solat.
Same place, same date.

Even though Google claimed that the calculation method is from Jabatan Kemajuan Islam Malaysia (JAKIM), then why the time is slightly different between the two?

[iqfareez]

There are few criteria that affects the prayer time calculations:

Calculation Method

Basically, the difference is with the Fajr and Isya angle

Value	Description
muslim_world_league	Muslim World League. Fajr angle: 18, Isha angle: 17
egyptian	Egyptian General Authority of Survey. Fajr angle: 19.5, Isha angle: 17.5
karachi	University of Islamic Sciences, Karachi. Fajr angle: 18, Isha angle: 18
umm_al_qura	Umm al-Qura University, Makkah. Fajr angle: 18, Isha interval: 90. Note: you should add a +30 minute custom adjustment for Isha during Ramadan.
dubai	Method used in UAE. Fajr and Isha angles of 18.2 degrees.
qatar	Modified version of Umm al-Qura used in Qatar. Fajr angle: 18, Isha interval: 90.
kuwait	Method used by the country of Kuwait. Fajr angle: 18, Isha angle: 17.5
moonsighting_committee	Moonsighting Committee. Fajr angle: 18, Isha angle: 18. Also uses seasonal adjustment values.
singapore	Method used by Singapore. Fajr angle: 20, Isha angle: 18.
north_america	Referred to as the ISNA method. This method is included for completeness but is not recommended. Fajr angle: 15, Isha angle: 15
kuwait	Kuwait. Fajr angle: 18, Isha angle: 17.5
other	Fajr angle: 0, Isha angle: 0. This is the default value for method when initializing a CalculationParameters object.

Source: https://github.com/iamriajul/adhan-dart#calculation-parameters

Also, from another sources:

Source: http://praytimes.org/calculation

Mazhab

Value	Description
shafi	Earlier Asr time
hanafi	Later Asr time

Source: https://github.com/iamriajul/adhan-dart#calculation-parameters

Ini kerana Hanafiyyah berpegang bahawa solat asar bermula apabila bayang-bayang suatu objek panjangnya dua kali objek asal, sedangkan Jumhur berpendapat apabila bayang-bayang panjangnya sama dengan objek asal dan lebih sedikit

Source: https://www.muftiwp.gov.my/artikel/al-kafi-li-al-fatawi/1226-al-kafi-375-perbezaan-masuk-waktu-solat-fardu-asar

Also, TIL that Masjid India were practicing Asar Hanafiah: https://twitter.com/acaiijawe/status/1041663979691491329?s=20

High Latitude Rule

Value	Description
middle_of_the_night	Fajr will never be earlier than the middle of the night and Isha will never be later than the middle of the night
seventh_of_the_night	Fajr will never be earlier than the beginning of the last seventh of the night and Isha will never be later than the end of the first seventh of the night
twilight_angle	Similar to SEVENTH_OF_THE_NIGHT, but instead of 1/7, the fraction of the night used is fajrAngle/60 and ishaAngle/60

Source: https://github.com/iamriajul/adhan-dart#calculation-parameters

Learn more about higher latitudes on http://praytimes.org/calculation#:~:text=2(Fajr%20%2D%20Sunset).-,Higher%20Latitudes,-In%20locations%20at

[iqfareez]

From https://www.salahtimes.com/malaysia/settings, the Malaysia parameters are as follows:

• High Latitude Methods: N/A
• Prayer Methods: Muslim World League
• Supported Asar Methods: Syafie

However, the value if slightly off:

Salahtimes	JAKIM

[iqfareez]

Some additional resources we can read to understand each prayer times were calculated in Malaysia.
But, I'm not sure how updated there are:

1. https://nshahida29.wixsite.com/e-falak-syarie/tafsiran-astronomi-waktu-solat-1
2. https://www.e-solat.gov.my/web/index1.php?id=55&type=A http://web.archive.org/web/20180728223104/https://www.e-solat.gov.my/web/index1.php?id=55&type=A

PDF receipt for [2]: Tafsiran-astronomi-waktu-solat.pdf