Shavuot, if it were a person, might have a complex about its many names, since it has five:
Shavuot - The "Festival of Weeks." The Passover-to-Shavuot countdown.
Zman Matan Torateinu - Literally, the "Time of Receiving our Torah." In the Jewish classic "To be a Jew" (Basic Books, 1972), Rabbi Hayim Halevy Donin writes that the word "receiving" is used-rather than "giving"-because while the giving happened once, "The receiving of the Torah by Jews must continue to take place every day." If ever there's a rabbinical answer, that's it.
Chag HaBikkurim - "Holiday of the First Fruits," when the fruit harvest begins. The first fruits of the seven fruits of Israel-wheat, barley, grapes, figs, pomegranates, olives, and dates-were also brought to the Holy Temple for an offering.
Atzeret - "Conclusion," which refers to the end of the period that began with Passover, as if the seven weeks were one long holiday.
Chag HaKatzir -- The "Festival of Harvest," since the holiday takes place at the time of year when wheat is harvested.
