Ten Days of Repentance
(Hebrew: עשרת ימי תשובה/ Spelling: Aseret Yemei Teshuva, Aseres Yemay Teshuvah / Other Names: / Definition: Period of ten days on the Jewish calendar beginning on Rosh Hashana lasting until after Yom Kippor dedicated to self improvement and repentance.)
Aseret Yemei Teshuva is the name given to the Ten Days of Repentance at the start of the new Jewish calendar year. Starting with the first day of Rosh Hashanah the Aseret Yemei Teshuva last until after Yom Kippor. These ten days are a time for self analysis, repentance and preparation for the final judgment by Hashem on Yom Kippor.
 Asking Friends for Forgiveness
Unlike other transgressions in the Torah, sins between one man and another are not forgiven on Yom Kippor until an apology is attained from the offended individual. During the Aseret Yemei Teshuva many people take the opportunity to ask friends, neighbors and associates to forgive any wrongdoings they have committed against them. In accordance with Judaism, individuals are asked to be forgiving when offered an apology and not to continue holding a grudge.
It is customary to do Kapparos during the Aseres Yemay Teshuvah, preferably on Erev Yom Kippor. It is the custom of some to preform the Kapparot with a live chicken or fish, while others preform the ritual using money. After the ritual, the slaughtered chicken or money is given to poor people.
 Erev Yom Kippor
It is a great Mitzvah to eat and drink on Erev Yom Kippor. A number of customs and rituals are preformed on Erev Yom Kipor in preparation for the holy day.
 Eating and Drinking
So great is the Mitzvah of eating and drinking on Erev Yom Kippor that when a person does so it is considered as if he fasted two days, Yom Kippor and the previous day. Eating and drinking is a way of showing our happiness at Hashem's mercy for giving us an opportunity to attain forgiveness each year. It also serves as a preparation for the physical fasting, to make the fast easier and reduce the risks of having to violate the fast by eating. It also shows that Judaism is not a religion based on self torment.
Although one is supposed to increase his intake of food and drink on Yom Kippor he must refrain from eating things that increase seed and could cause Keri.
It is customary to give a lot of charity on Erev Yom Kippor and to settle all outstanding debts, especially to charitable causes.
 Seudah Mafseket
A large meal called Seudah Mafseket is eaten on Erev Yom Kippor. One should eat the meal after praying Mincha, which contains the vidoy prayer. This way if he chokes and dies during the last meal before Yom Kippor, at least he first recited the Vidoy. One must end the Seudah Mafseket before candle lighting.
 Birchas Habonim
Many people have the custom to bless their children right before heading out for the Yom Kippor services. A father places his hands on the head of his child an recites the traditional Birchas Kohanim. He then adds in his own words any addition blessings he wishes to bestow upon his child.
 Yom Kippor
Many people have a custom to wear white on Yom Kippor as a sign of purity and forgiveness. It is best not to wear any gold items to avoid reawakening a remembrance of the Sin of the Golden Calf.
 Yom Kippor Services
Yom Kipor services are the longest in the entire year, most of the day is spent praying in Synagogue. It is the only time during the year when the phrase 'Baruch Shem' is recited out loud.
 Tefillah Zakah
Tefillah Zakah means a prayer of purity. It is a few pages long and is recited right before the Kol Nidray prayer on Yom Kippor night. In Tefillah Zakah a person confesses for all the sins he has committed. A strong emphasis is placed on sexual sins, especially the severe sin of spilling seed.
 Kol Nidre
Kol Nidre should be recited before sunset at the start of the prayers on Yom Kippor night. During the Kol Nidre prayer a Torah scroll is removed from the Arc and is walked around the congregation. Kissing the Torah is a Tikkun for any improper kissing done. At the start of the Kol Nidre prayes, the Chazen requests permission from the heavenly court to allow the prayers services to take place even though the Minyon is made up of transgressors. After this is recited three times a prayer composed to absolve any vows made during the upcoming year is recited three times, with each proceeding time in a louder voice.
 Yom Kippor on Shabbos
When Yom Kippor falls out on Shabbos a number of small editions are inserted into the prayers as a remembrance of the Shabbot.
Vidoy is a detailed confession of many sins. It is composed of four sections after each one forgiveness is asked for all the sins that were just confessed. Vidoy is recited on all Yom Kippor prayers, including Mincha of Erev Yom Kipor but Excluding the Neilah prayer. Vidoy is also recited a second time in each prayer as part of Chazoras Hshatz.
 Neilah Service
After Mincha and right before sun set the Neilah prayer is recited. Neilah is the last opportunity to repent and change what is decreed for the upcoming year. Neilah means to 'lock', it is the last chance to pray before the heavenly gates are locked up for the upcoming year. During the Neilah, we ask Hashem to seal our fate in the various books of life, as opposed to the earlier prayers where we just request to be 'written'. Neilah is the only time during the entire year where a fifth prayer is added to the daily service.
 Accepting Rulership of Hashem
After Neilah it is customary to do Kabbalas Ohl Malchut Shamaim. First the the Shliach Tzibor recites the opening verse of Shema along with 'Boruch Shem', he is then followed by the rest of the congregation. Afterwords the verse 'Hashem who HaElokim' is recited seven times in a similar fashion, to declare that Hashem controls all powers of the world.
 Motzai Yom Kippor
Havdala flame should be lit from a Yortzit candle that was lit before Yom Kippor. A celebration meal is eaten to show our happiness and thanks to Hashem that our sins were forgiven. It is customary to start construction of the Sucka on Motzai Yom Kippor, to go from one Mitzvah into another.