"Rabbi Shimon said, 'Pesach and Sukkot, which do not fall during times that work is done in the fields, this one (Pesach) is seven days, and the other (Sukkot), eight. Atzeret (Shavuot), which falls at a time when work is done in the fields, is only one day - to teach that the Torah has mercy on the Jewish People.' " (Sifri, Parshat Re'eh)

As with all of the Jewish Holidays, the Laws and Service of the Day are intertwined. For our holidays are days of special service to the "Ribbono shel Olam," the Master of the Universe, Whose Written Torah decreed, and Whose Oral Torah defined and expanded upon, the
Laws associated with those days.

Z'man Matan Torateinu
The Time of the Giving of Our Torah

All the prayers and the Kiddush of this holiday are similar to the prayers and the Kiddush of the others of the Three Regalim (the others: Pesach and Sukkot), with the exception that Shavuot too has its own unique description: "et yom chag HaShavuot hazeh, zeman matan torateinu," "this Day of Shavuot, the time of the Giving of the Torah."

In the Mussaf Prayer, the Additional Prayers include mention of the unique sacrifice associated with Shavuot, including the "Two Breads," the Grain Offering brought on the "fiftieth day," so to speak, after the bringing of the Omer on the second day of Pesach. This Offering was brought from "new wheat."

Mussaf Prayer
Additional Prayer

The description of the Additional Offering of Shavuot is introduced by the following paragraph: (transliteration and translation of the paragraph taken, with permission, from the Seif Edition of the SABBATH AND FESTIVAL SIDDUR, published by ArtScroll as an Orthodox Union Centennial Publication, with Introductory Essays and Comments by Rabbi Benjamin Yudin)

UVYOM HABIKURIM,
And on the day of the first fruits,

B'hak-riv'chem mincho chadosho Ladonoy,
When you bring a new meal offering to Hashem,

B'shovu-osaychem,
On your Festival of Weeks;

Mikro kodesh yih-ye lochem,
There shall be a holy convocation for you,

Kol m'leches avodo lo sa-asu.
You may not do any laborious work.

Other Prayer-ful Features of Shavuot

Hallel is completed, as it is on the other "Regalim."

When the Kiddush is recited, the "bracha," or blessing, of "She-he-cheyanu," "the One Who kept us alive," is included. When the woman-of-the-house, in general, makes the blessings on the candles, she includes that bracha as well, before the candles are lit.

Even though on every other "Erev Yom Tov," Holiday Eve, the Evening Services are begun somewhat earlier, in order to be "mosif min ha-chol al ha-kodesh," "to add from the mundane time to the holy time," on Shavuot we specifically do not do that!

Because the Torah says that "sheva shabbatot t'mimot," "seven complete weeks" should transpire before Shavuot, and if we start early, that "t'mimiyut," or "completeness" will be lacking!

Kiddush should also not be recited before it is definitely night-time (three medium-size stars should be visible in the sky).

No "Chol HaMoed"
No Intermediate Days

One way in which Shavuot differs from the other Regalim is in its length. Pesach, in the Torah (and as celebrated in Israel) is defined as a seven-day celebration. Sukkot (including Shmini Atzeret), in the Torah (and as celebrated in Israel) is defined as an eight-day holiday. Shavuot is only celebrated, again, as defined in the Torah and as celebrated in Israel, as a one-day holiday.

Why is this so?

A possibility for the "why" behind this fact is, as mentioned in the header citation of this page, that the Torah does not want to keep the Jewish farmer, who has so much to do during this season, the season of the cutting of wheat and barley, away from his farm for longer than necessary. On the other hand, It is considered "necessary" for the farmer, as well as all Jews, to put in at least a brief appearance at the Temple, to "be seen" by G-d, in Jerusalem.

What has been surgically removed by Hashem, for the benefit of the Jew, is the period of "Chol HaMoed," the Days of "Chol," relative mundane-ness (eh?); that is, like weekdays, within the "Moed," the "bookends" of holy time. This period of Intermediate Days does not carry the same work restrictions as the holiday itself. The Period of Chol HaMoed is a combination of "Kodesh," holy and "Chol," mundane or less holy, which deserves, and which will receive a separate discussion. But this is not the place, especially because Shavuot does not have any Chol HaMoed.

"Yom Tov Sheni shel Galuyot" -
"Second Day of the Holiday" (Celebrated Only in Diaspora)

The meaning of this concept is that in the Diaspora, two days of holiday are celebrated where the Torah speaks of only one. The reason for this is that in the time of the Talmud, when communications were a very, very far cry from what they are now and, even when a procedure was initiated which could achieve fast communications, it was undermined by forces hostile to the Talmud and to the Rabbis.

What needed to be communicated was the time of Rosh Chodesh because the entire Hebrew Calendar is based on lunar calculations. A means was devised to communicate this information swiftly throughout Israel (nearly at the speed of light) and to the edge of the "Golah," the Diaspora, by means of the chain-lighting of torches on mountain-tops between Jerusalem and the outer limits of that area. But the method was sabotaged by the "Tzedukim," the Sadducees, who were not at all interested in helping the "Sanhedrin," the Jewish Supreme Court, where testimony concerning Rosh Chodesh was taken, solve its practical problems.

As a result, the solution settled upon was that messengers went out from the Sanhedrin to the outer limits of Israel and to the Diaspora to communicate when Rosh Chodesh had taken place. But this introduced an element of uncertainty in the Diaspora as to when Rosh Chodesh had taken place, and hence when the holiday should take place.

So the device of instituting a Second Day of Celebration in the Diaspora was introduced, whereby the "Second Day" was accorded the same significance as the First Day by decree of the Rabbis, into whose hands the scheduling of the holidays had, in any case, been placed by G-d, the One Who sanctifies Israel and the Holidays.

Nowadays, when there is no uncertainty as to when astronomical events take place, we still maintain the original custom instituted when there existed that uncertainty. This is called the Principle (the Uncertainty Principle?) of "Minhag Avoteinu B'Yadenu," "We continue to maintain the custom of our ancestors."

On the first day of Shavuot, the reading is from Parshat Yitro, in the Book of Shemot, from "In the third month after the Jewish People left Egypt" till the end of the Parshah. This reading covers the event of "Maamad Har Sinai," the stand of the Jewish People at Mt. Sinai, to receive the Torah.

The Maftir, the Second Torah Reading of the Holiday, comes from one of the sections of the Torah which deals directly with the Holiday of Shavuot, beginning "Uv'yom HaBikkurim," "The Day of the Bringing of the First Fruits."

The Reading from the Prophets on the first day of Shavuot comes from Yechezkel which deals with the mystical subject of the "Divine Chariot," which also deals with a Revelation of G-d in prophecy to an individual but, through his book, to all of Israel.

On the Second day in the Diaspora, the First Torah Reading is from "All the First Born," which deals with the various holidays, the second again from "Uv'yom HaBikkurim," and the Reading from the Prophets from Chavakuk, which deals with a vision of Hashem in His holy Palace.

On the Second Day in the Diaspora, and on the one day of Shavuot in Eretz Yisrael, Megillat Ruth is read after Hallel. Various reasons for reading the Megillah on Shavuot are given. Some are as follows:

1. The conversion of Ruth to Judaism was by a painful route, as seen in the Story of Ruth, just as the acceptance of the Torah by the Jewish People was via the painful route of years of slavery in Egypt!
   
   
2. The time of the year in which the events of the Megillah took place was in the grain-cutting season, as it says "in the beginning of the cutting of barley," and one of the names of Shavuot is "Chag HaKatzir," the Holiday of Grain Cutting.
   
   
3. The law that allowed Ruth to join the Jewish People was based on the Oral Law. Because according to the Written Law, "No Amonite or Moabite may enter the Jewish People (by marriage)." The Oral Law differentiated between the male Moabite and the female Moabitess, because the exclusion was tied to the cruelty of those nations, and those cruel decisions were made exclusively by the males - to show the importance of the Oral Law in the Jewish System, in the role of providing definition and explication of the Written Law.

"Akdamut" and "Ketuvah"