As we get ready to usher in the holiday of Shavous, some points to ponder on the differences between our current names and associations for various holidays, versus how they are referred to in the Torah:
1) We refer to Shavous almost exclusively as Z'man Matan Toraseynu - the anniversary of God's giving the Torah on Har Sinai. Yet in the Chumash, Shavous is associated primarily with the count of seven weeks from Pesach - hence the name Shavous, "weeks" - as well as with the harvest (Chag Ha'katzir) and the first-fruits (Chag Ha'bikkurim). There is no mention anywhere in Tanach of this holiday commemorating the events of Har Sinai, even though the narrative of Exod 19 clearly places those events within at most a day or so of when Shavous falls.
2) Rosh Hashanah, of course, is the Jewish New Year - or is it? Again, in the Chumash it is only called "Yom Ha'zikaron" - day of remembrance, falling on the first of the 7th month, Tishrei. The name Rosh Hashanah for this holiday, and thus its connection with the start of a new calendar year, appears nowhere in the Torah.
3) Finally, we use the name "Pesach" to refer to the entire seven-day holiday of Passover (eight days outside of Israel). But throughout the Chumash and Tanach, "Pesach" always refers only to the time of bringing/eating of the Korban Pesach, the pascal sacrifice, on the afternoon/night of the 14th-15th of Nissan. The full seven-day holiday that runs from Nissan 15-21 is always "Chag Ha'matzos" in the Torah.
I have often wondered when, historically, these shifts in naming occurred. Clearly, it was sometime after the 1st temple era, yet before the codification of the Mishnah, by which point all three of the latter terms/associations were in common usage. If anyone know of research on this subject, please point me to it.
Meanwhile, a happy Shavous / Pentecost / Z'man Matan Toraseynu / Chag Ha'katzir / Chag Ha'bikkurim / Yomtiff to all!