Islamic Institute of Toronto is following the position of the Fiqh Council of North America on this issue. You should read the detailed article entitled Calculation for Crescent: A Reliable Method to Meet the Objective of Shari'ah by Dr. Muzammil H. Siddiqi on their website: http://www.fiqhcouncil.org/
You may also refer to my answer to a question posed to me on this issue on islamonline.net; I reproduce it below without modifications:
Dear Sheikh Ahmad, as-salamu 'alaykum. Recently, ISNA (Islamic Society of North America) decided to depend solely on astronomical calculations in determining the beginning and end of lunar months, including Ramadan.
They say that sighting the new moon by the human eyes is not an act of worship, but a means to know the beginning and end of lunar months. They argue that astronomical calculations can play that role and unite at least Muslims of America.
They announced the beginning and the end of the coming Ramadan. They even issued an Islamic calendar, based on the astronomical calculations, for some years to come. How do you see this issue?
Name of Counsellor
Wa'alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
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.
Thanks very much for your question, which comes at a critical time for North American Muslims.
Before responding to your question, we would like first to direct the attention of Muslims in North America and elsewhere to the paramount importance of unity and solidarity. We call upon all Muslims in North America, especially those with a view opposing ISNA's, to put their unity as a community as a priority before delving into internal differences on this issue.
Moreover, it is high time for us to truly base our approaches concerning juristic issues on the pristine sources of Islam. We should stop feeding animosity. Critical issues like this should be judged with wisdom while placing the unity of Muslims as a top priority. If we consider all this and kept in mind that ISNA has made a real contribution to North American Muslims and made their unity a priority, then we will see that we should not promote our differences to the detriment of the well-being of Muslims.
Responding to the question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states the following:
I can very well agree with the decision of ISNA Fiqh Council on this matter. Such a decision is long overdue. My reasons for this are the following:
1. During the time of the Prophet (peace and blessings be upon him), sighting the new moon with the naked eyes was the only means available for the people, as he himself said: "We are a people who are unlettered." He did not mean that he would like his people to stay at that level forever. Given the condition of his time, naked-eye sighting was the only possible choice.
2. We know from evidence that the Prophet (peace and blessings be upon him) used every opportunity to lift the Ummah out of illiteracy to literacy and civilization.
3. The Qur'an provides ample evidence for scientific observation of the sun and the moon. Astronomy today is a science that is based on observation of the position of the sun and the moon. So by following scientific methods of calculations, we are still observing the moon but not by naked eyes, rather by far more precise instruments. Therefore, we are not contradicting the original intent of the Prophetic dictum that orders us to observe the moon.
4. The fact that the scholars of the past did not base the beginnings of months on scientific calculations cannot be used as an argument, for in their time, there was little difference between astrology and astronomy. Today astronomy is a science. The Qur'an already taught us that the sun and moon revolve in their own orbits and that they follow fixed divine laws. They do not run erratically, so there is an observable pattern to be discovered through observation, which is what scientists do. That is why Imam Subki and others also supported calculations even before the snowballing of scientific knowledge.
Furthermore, by following calculations we can facilitate the observance of the festivals and plan for them way before their time. This is a great maslahah (public interest) for those living in the West. The principle of taysir (facilitation) is a great consideration that we can never dispense with in this time and age.
In conclusion, for reasons mentioned above and others, I agree with ISNA's position. This would be a great step for moving the Ummah towards a united position.