When is Pentecost?

1And when the day of Pentecost was fully come, they were all with one accord in one place. 2And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. 3And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. 4And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance. 5And there were dwelling at Jerusalem Jews, devout men, out of every nation under heaven. 6Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language. 7And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galileans? 8And how hear we every man in our own tongue, wherein we were born? 9Parthians, and Medes, and Elamites, and the dwellers in Mesopotamia, and in Judea, and Cappadocia, in Pontus, and Asia, 10Phrygia, and Pamphylia, in Egypt, and in the parts of Libya about Cyrene, and strangers of Rome, Jews and proselytes, 11Cretes and Arabians, we do hear them speak in our tongues the wonderful works of God. 12And they were all amazed, and were in doubt, saying one to another, What meaneth this?