I posted another comment basically agreeing with yours, that there are different dates given for Pentecost.

May 27 is the standard one on both the modern calendars and the rabbinical calendar in use today.

But there are groups on the net, and individuals, who have other dates in mind.  I cannot keep up the complex

and varied thoughts about the date.  The main thing to remember is that it's a wheat harvest in Israel.  A harvest

coming not easily as Barley on First Fruits, but with Tribulum (the device used to separate wheat and chaff).

I can easily see a picture of ten days of tribulation going on now between Ascension and the standard date of

Pentecost.  Many Doves' posts indicate that they are disturbed more than usual about what's "going on".  They are 

in "Tribulum."  

Yes, there have been several Doves who referred to alternate Pentacost dates, including Ila Olori who posted

recently, and Eliane B who has not posted for a while.  Both have dates in July, I believe.  There are

even some who put it later, but I think the wheat harvest is mostly over by August, even in cooler climates,

but I could be wrong.  It's the fruit that is traditionally harvested in summer, then the beginning of olives, and

olives extends into November, a long gathering season. 

I looked up dates of grain harvest in Israel and it is mid April to mid May in the most productive areas, such 

as the coastal valleys.  Northern Israel, where it's harder to grow wheat because of climate, may harvest after

May 27, but mostly modern Jews use May 27. 

Mariel Rowina