The period between Rosh Hashana and Yom Kippur are called the Ten Days of Repentance. Or in Hebrew it is known as the Aeres Yemei Teshuva.
On Rosh Hashana, the righteous and the wicked receive their judgment. One should not see himself as wicked or be so presumptuous as to consider himself righteous. Therefore we have 10 days to improve and tip the scales to the side of righteousness. Yom Kippur is the culmination of this period.
During the Ten Days of Teshuva, Jews engage in intense introspection for the purpose of self-improvement. We become more scrupulous in the observance of mitzvot.
THE CUSTOM OF KAPAROT
If God ruled the world by strict justice, then every time a person would do something purposely wrong, a giant 100-ton weight would fall from the sky and squash him. Fortunately for us, God also rules by mercy and allows us to gain atonement.
One of the methods of atonement is through the ritual of Kaparot. This is done by taking a chicken, or money, and waving it around your head three times. The chicken is then slaughtered and given to charity (as is the money if used in place of the chicken).
The point of using a chicken is to show us the volatility of life. One minute the chicken is alive the next minute it's not. And if God had ruled by strict justice, our lives might have gone as fast as the chicken's!
This will certainly help a person understand the severity of the Ten Days of Teshuva.
While swinging the chicken (or money) above your head, say:
"This is my exchange, this is my substitute, this is my atonement. This rooster is going to die (or this money will go to charity), but I am going to a good long life and to peace."
The full text can be found in any siddur or Yom Kippur Machzor.
CHANGES IN THE PRAYERS
Havdallah is recited at the conclusion of Rosh Hashana, but only the blessing on wine and the final blessing.
If Rosh Hashana falls on Saturday night, "V'todianu" is added in the fourth blessing of the "Amidah."
The third of Tishrei, the day after Rosh Hashana, is a public fast day called Tzom Gedaliah. All the laws of the minor fast days apply. The fast begins at dawn and ends at nightfall.
There are several small but important changes in the daily prayers that should be noted.
These are the changes to be made in the "Amidah:"
- In the first blessing, we add the sentence "Zachreinu l'chaim."
- In the second blessing, we add the phrase "Mi chamocha."
- In the third blessing, we conclude with "Hamelech Hakadosh," instead of the usual "Ha'El Hakadosh." If this is not done, the entire Amidah must be repeated. (The other additions do not require one to repeat the Amidah.)
- In the 11th blessing, we conclude with "Hamelech Hamishpat," in place of "Melech Ohave Tzedekah U'mishpat."
- In the 18th blessing ("Modim"), we add the sentence "U'ch'tov l'chaim."
- In the final blessing ("Sim Shalom" or "Shalom Rav") we add the sentence "B'sefer chaim."
The prayer "Avinu Malkeinu" is said after the repetition of the "Amidah" in the morning and afternoon.
In the "Kaddish," we say "l'ailah u'l'ailah mikol," instead of the usual "l'ailah min kol."