Easter and The Feast of First Fruits are both always on a Sunday. This year, they were both on the same Sunday. Therefore this year Petacost Sunday and The Feast of Pentacost (also always Sunday) will both fall on the same day too. 50 days from Easter is June 12th though. The nature of 50 days, is the same day of week at end of count.
For "regular" Christians, Pentacost starts at Either midnight to count the day. Or at Sunrise to celebrate the Resurection of The Christ.
For "messianic" Christians or those who believe in the keeping of The Feasts of The Lord, The Feast of Pentacost starts at sunset of June 11th.
Some interesting facts about the date of Pentacost.
Sorry Nicodemus, somehow as I read I missed your reply, but this is still usefull added info.
"As you have done unto the least of these my brethren, you have done it unto Me." Yeshua.....