1. Blowing the Shofar

On Rosh Hashanah the principal Mitzvah (precept) is to blow (or listen to) notes on the Shofar - a ram's horn. Every Jew is obliged to listen to at least 30 'sounds'; in the Synagogue it is customary to blow 100 notes. There are special laws on how the Shofar is blown. The order of sounds is:

Tekiah Shevarim-Teruah Tekiah
Tekiah Shevarim Tekiah
Tekiah Teruah Tekiah

(Each of the above counts as a note; Shevarin-Teruah counts as two notes.) Tekiah is a continuous sound, shevarim is a triple note, teruah is a set of staccato notes.

The Shofar is not blown on Shabbat.

2. Prayers

The Amidah prayers in the Maariv (evening service), Shacharit (morning) and Minchah (afternoon) are constructed on the basis of seven blessings, as on Shabbat (the Sabbath) and other festivals.

The amidah in the Musaf (additional service) contains nine blessings: the three middle ones are the malchuyot (proclaiming G-d as Supreme King or Judge), zichronot (G-d's remembrance of His promises) and Shofarot (the blowing of the Shofar on various occasions).

3. Torah Readings

On the first day, about the birth of Isaac (Genesis 21);
On the second day, about the Akedah - the binding of Isaac (Genesis 22);
Maftir, on both days, about the festival sacrifice (Numbers 29:1-6);

4. Tashlich

On the first day of Rosh Hashanah , after Minchah (afternoon prayers), it is customary to go to a river (or the sea) and read the last three verses of the Book of Micah (7:8-20).

5. Festive Meal

At the evening meals, it is customary to eat foods that allude to renewal, a good year through mitigation of the decree of judgement, prosperity, and a good and sweet year.

- One particular custom at the beginning of the meal is to dip a slice of apple in honey and eat it, after saying a special prayer for a good and sweet year.
- Some people avoid eating nuts, because the numerical value (gematria) of the Hebrew word for 'nut' is almost equal to that of Hebrew word for 'sin'.

6. Greetings

People greet each other with the wish,

'May you be inscribed (i.e., in the Judge's book of decrees) and confirmed for a good year and a good life'.

7. The Long Day

It is customary not to sleep during the day, but to spend most of the time in prayer and Torah study.

8. Clothing

For Erev Rosh Hashanah (the Festival eve) clothes are washed (if necessary) and it is customary to have a haircut, in honor of the festival. On Rosh Hashanah, white clothes are worn as a sign of purity before judgement.

9. Annulment of Vows

On Erev Rosh Hashanah (the last day of Ellul), after the morning service (or, according to the Sephardi custom on the first day of Ellul) it is customary to annul vows.

10. Eruv Tavshilin

If the first day of Rosh Hashanah falls on Wednesday night, eruv tavshilin (a portion of food and bread from the Shabbat meal) is set aside with the appropriate statement being read, on Erev Rosh Hashanah (i.e. Wednesday), so that food may be cooked on the Friday for the Sabbath.