Asara B’Teves is Tuesday, January 3rd. It is a day of prayer and fasting mourning the siege and destruction of Jerusalem, the translation of the Septuagint and other national travesties.
Let’s use this opportunity for introspection and to merit to greet Mashiach and see the rebuilding of the Beis Hamikdash.
Source: Chasam Sofer - Commentary to the Selichos for Asarah B’Teves