ימי הסליחות (Yemei HaSelichot) refer to the days of Selichot, which are special penitential prayers recited in preparation for Rosh Hashanah and Yom Kippur. The Selichot prayers focus on themes of repentance, forgiveness, and introspection, asking Hashem for mercy and compassion as the new year approaches.

When Selichot are recited:

• Sefardim: Begin reciting Selichot at the start of the month of Elul, and continue every day until Yom Kippur.
• Ashkenazim: Begin reciting Selichot on the Saturday night before Rosh Hashanah. If Rosh Hashanah falls earlier in the week, they start the week before, ensuring there are at least four days of Selichot leading up to Rosh Hashanah.

The Selichot prayers are typically recited early in the morning, before dawn, as this time is considered especially auspicious for seeking forgiveness. The prayers include supplications, confessions, and the recitation of the 13 Attributes of Mercy (י"ג מידות הרחמים), which emphasize Hashem's compassion and readiness to forgive.

These days are seen as a time of heightened spiritual awareness, where individuals and communities focus on תשובה (teshuvah), repairing their relationship with Hashem and preparing for the upcoming Days of Awe.