Yom Kippur comes on 10 of Tishrei.
It is the most serious and responsible day in life of the Jew. This day the destiny of each person the next year finally is solved. It is considered, that in Rosh Hashanah G-d writes down each Jew in one of three books - the book of rithteous persons, the book of sinners and the book of average, and in Yom Kippur seals.
Time between Rosh Hashanah and Yom Kippur refers to Terrible days; these days the person still has opportunity to affect a verdict which G-d bears in Rosh Hashanah. About it is told in one of the prays readable in Yom Kippur : « But tshuva (repentance), fphila (pray) and tsdaca (donations) cancel a heavy verdict ». It is necessary to repent of the sins and to try to correct that is possible. It is necessary to ask also a pardon for people and G-d for the offences accomplished against them.
In days of existence of Temple Yom Kippur was in the unique afternoon when first priest entered in Sacred of Sacreds the Temple, said the Name Supreme and asked in God a pardon of the sins and sins of all people of Israel.