Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
There is nothing wrong with following the lunar calendar for Muslim celebrations of fasts and Eid festivals as we follow the solar calendar for determining the times of prayers.
Responding to the question in point, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
Following the lunar calendar for Muslim celebrations
I do not find any difference between following the lunar calendar for Muslim celebrations of fasts and Eid festivals as we follow the solar calendar for determining the times of prayers.
The Quran states that sun and moon move in computed orbits and thus not erratically; the Quran also implies that we can make calculations and calendars accordingly.
Why didn’t Prophet Muhammad follow calculations?
The fact that the Prophet Muhammad (peace be upon him) did not follow calculations cannot be used as an argument against this for he clearly explained why he did not follow the method of calculation.
While opting for the physical sighting of the moon, he said, “We are a community who do not know how to read and calculate!”
In other words, given the state of the Ummah at the time, it would have been next to impossible for them to resort to calculations. We also ought to remember that the Prophet was the one who took the Arabs out of the state of illiteracy, seizing the earliest opportunity to do so. Thanks to his efforts, they were raised to become leaders of civilization in literacy and learning the arts and sciences.
Those who refuse to accept the calculation should explain why then they are following prayer time tables when the Prophet never used them; instead he acted on the physical observation of the positions of sun to determine the prayer times.
I do not see any reason to make such a distinction.
That is why several eminent scholars, jurists, and expert traditionists have ruled in favor of calculations in regard to observing fasts and Eid celebrations.
The Fiqh Council of North America has chosen this position; it has been a source of great comfort and ease for Muslims in North America, saving them from confusion.
Almighty Allah knows best.