The Islamic Society of Central NY Salat ul Eid announcement was determined by calculation and per the guidance of the Fiqh Council of North America.
Below is a repost from the Fiqh Council of North America website.
Eid al Fitr on Friday, June 15, 2018
“O you who believe, fasting is prescribed to you as it was prescribed to those before you, that you may (learn) self-restraint.” Qur’an 2: 183
The Fiqh Council of North America recognizes astronomical calculation as an acceptable Shar’i method for determining the beginning of Lunar months including the months of Ramadan and Shawwal. FCNA uses the criteria of European Council of Fatwa and Research (ECFR), which are that somewhere on the globe, at the sunset, the elongation should be at least 8 degrees and moon should be at least 5 degrees above the horizon. If this condition is met the month starts the next day, otherwise, the month starts on the day following next.
On the basis of this method the dates of Ramadan and Eidul Fitr for the year 1439 AH are established as follows:
Ramadan 1439 AH:
The Astronomical New Moon is on Tuesday, May 15, 2018 at 11:47 Universal Time. On that day, somewhere in the Pacific Ocean at sunset, the elongation is 8 degrees and moon is 5 degrees above the sun. Therefore the first day of Ramadan 1439 is on Wednesday, May 16, 2018, insha’Allah. First Tarawih prayer will be on Tuesday night.
Eid ul-Fitr 1439 AH:
The Astronomical New Moon is on Wednesday, June 13, 2018 at 19:43 Universal Time. On that day there is no place on earth where at sunset the elongation is 8 degrees and moon is 5 degrees above the sun. Therefore, Shawwal cannot start the next day. Hence, the first day of Shawwal 1439 is on Friday, June 15, 2018, insha’Allah