Intuitive Application for Yearly Lunar(Hijri) Calendar using probability of Local Hilal Sighting

Intuitive Application for Yearly Lunar(Hijri) Calendar using probability of Local Hilal Sighting

Please also see for Islamic Dates 2013.
 Blog: Islamic Dates 2013: Preventing different dates for Essential Events (Ramadhan and EIDs)

Yearly Lunar(Hijri) Calendar ( Hijri Date As per Local Hilal Sighting instead of Global Sighting)

Assalaamu Alaikum (Peace be upon you)! Brothers/Sisters,
I feel delighted to share with you a highly intuitive application, powered by Google Code; that predicts Hijri dates for years ( 1990 to 2020), using mathematical calculations and available astronomical data,  99% accurate and tested against available data and Visibility graphs etc. The flyer attached above is an instruction manual for understanding color codes used in application and other Technical details.

This is the application.http://azizahijricalendar.appspot.com/

The application when loads, determines the current year's all possible Hijri months Start dates, for certain pre-selected cities which are of interest to general people. However one can choose Cities of His Choice, and change the year if needed.

• If you change the year (and tab out), the page refreshes automatically to return data for the chosen year ( NO need for pressing Submit)
• After you choose Cities of your Choice,  Just press Enter key, and the page refreshes automatically to return data for the chosen Cities( NO need for pressing Submit)
• For seeing the visibility graphs, don't forget to Click the Details link for particular place/Hijri Month.
• For further instructions, don't forget to read the Flyer (picture) attached above.

The application determines all necessary parameters ( see Details link ) which are of utmost relevance and of perfect understanding for an average person sighting the moon viz.

The application uses almost all criterias used by modern day Astronomers, viz.

• Elongation of moon at Sunset (angle of Separation between Sun-Moon)
• Moon Altitude at Sunset
• Solar Declination at NoonTime
• Lunar declination at SunSet
• **Moon Latitude at Sunset
• Moon Earth Distance on the Day of Hilal( 384400 +- delta)
• Instanteneous Orbital velocity of Moon (based on Kepler's Law,See formula
• Crescent Width @ Sunset
• Crescent Probability is determined in % as

 (q% = Moon Altitude Factor% + Moon Age Factor%)

**Moon Latitude at Sunset The lunar orbit plane is inclined to the ecliptic (the plane of the Earth's orbit around the Sun) by 5.14°. Moon's maximum and minimum declination also varies because of this inclined orbital plane. Moon's Latitude is the angle subtended by moon over Earth, with Eliptic Plane as the base, which gradually changes from +5.14 to -5.14 over a period of ~T/2 days ( T~ 27.3 days), alternately adding to or subtracting from the 23.5° tilt of the Earth's axis.
As a consequence, the maximum declination of the Moon (Lunar declination) varies from roughly (23.5° - 5°) = 18.5° to (23.5° + 5°) = 28.5° .

The intention for developing this application, is not to declare any future Hijri date with any certainty, but to determine %chances for future 
special Lunar events like EID / Ramadhan etc, and to generate awareness among masses to understand that False sightings do take place in most countries including Saudi Arabia.  

Watch further this post for Hilal Sighting, Astronomy & Islamic Lunar calendar - Issues and Solutions

As time progresses, inshallah this application would remove all possible errors, and for that I am ready for any suggestions (Technical or Interface issues). 

Please leave your feedback/ suggestions by adding comments below, and dont forget to share with your friends, if you like it!

Jazakallah Khair
MA Naim