When do Christian's say Pentecost happend?

Answer 1

Acts 2:1
When the day of Pentecost came, they were all together in one place.

May I say to you that I love these things. They are so spectacular. They are a phenomenon that evades Christian and Jew alike. They are not paid attention to like they ought to be.

According to this source:
http://dictionary.reference.com/browse/Shavuot

is the following explanation:

Shavuot
–noun Judaism.
a festival, celebrated on the sixth and seventh days of Sivan by Orthodox and Conservative Jews outside Israel but only on the sixth day by Reform Jews and Jews in Israel, that commemorates God's giving of the Ten Commandments to Moses.

What Jesus claimed to do was fulfill the Law of Moses. The Ten Commandments was given by God through an old covenant. The new covenant was better though, for no one could fulfill the Law by their own effort, and it made no one anything but condemned, for the covenant was broken by sinners continually.

So Pentecost happened to commemorate the giving of the Ten Commandments by God to the Hebrews, and then on one of those occasions the Holy Spirit came down to the world of men to dwell in them, putting the Law in their minds, and writing them on their hearts.

Jeremiah 31:33
"This is the covenant I will make with the house of Israel after that time," declares the LORD. "I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people."

And so God's word is fulfilled. No longer is there a time when men must look and wonder what the truth is, what God wants and what He expects, because one greater than the tablets of stone was handed down to men; the Spirit of the Living God Himself.

Answer 2

It was the Jewish feast of Shavuot (which is also called Pentecost in the Greek) that happened after the death and resurrection of Jesus. It is found in Acts Chapter 2.

Traditionally, this is celebrated forty days after the Feast of the Ascension

Edit: oops fifty days after Easter

Answer 3

Pentecost means fifty, 50 days after Easter/resurrection day. It was10 days after Christ's ascension into Heaven

Pentecost was a day fulfilling the prophesy of Joel 2:28, 29, "And it shall come to pass afterward, that I will pour out My Spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions: and also upon the servants and upon the handmaids in those days will I pour out My Spirit."

Answer 4

I believe it was some 30 days after Jesus ascended into Heaven.

Edit: Ah, 40 days. My mistake.