According to the Fiqh Council of North America, the first day of fasting Ramadan will be Friday, April 24, 2020.

You who believe, fasting is prescribed for you, as it was prescribed for those before you, so that you may be mindful of God.
Fast for a specific number of days, but if one of you is ill, or on a journey, (make up the fast) on other days later. For those who can fast only with extreme difficulty, there is a way to compensate–– feed a needy person. But if anyone does good of his own accord, it is better for him, and fasting is better for you, if only you knew.

It was in the month of Ramadan that the Quran was revealed as guidance for mankind, clear messages giving guidance and distinguishing between right and wrong. So any one of you who is present that month should fast, and anyone who is ill or on a journey should make up for the lost days by fasting on other days later. God wants ease for you, not hardship. God wants you to complete the prescribed period and to glorify God for having guided you, so that you may be thankful.  ( Quran 2:183-185 )

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 around the globe, at sunset, the elongation should be at least 8 degrees and the moon should be at least 5 degrees above horizon. If these conditions are met, the new crescent will be visible somewhere on earth. Hence the new lunar month will start the next day, otherwise it will start on the day following that next day.

On the basis of this method, the dates of Ramadan and Eid ul Fitr for the year 1441 AH are established as follows:

Ramadan 1441 AH:

The Astronomical New Moon is on Thursday, April 23, 2020 at 2:27 Universal Time. On that day, everywhere in North and South America at sunset the elongation is at least 8 degrees and the moon is at least 5 degrees above the sun. Therefore, first day of Ramadan 1441 is on Friday, April 24, 2020, insha’Allah. Tarawih prayer will start on Thursday night.

Eid ul-Fitr 1441 AH:

The Astronomical New Moon is on Friday, May 22, 2020 at 17:40 Universal Time. On that day there is no place on earth where at sunset the elongation is 8 degrees and the moon is 5 degrees above the sun. Therefore Shawwal 1441 cannot start the next day. Hence first day of Shawwal is on Sunday, May 24, 2020, insha’Allah.

( Source: Fiqh Council of North America )