Fast of Tevet

The 10th of Tevet is the day on which the Babylonian siege of Jerusalem began. This one event caused a chain reaction that led to the eventual destruction of the Temple.

What does Asarah BeTevet mean?
Asarah in Hebrew means "10" and BeTevet means "in Tevet". It is simply then "The 10th of Tevet".

What are the customs of Asarah BeTevet?
The fast begins, as do all the public fasts with the exception of Tishah B'Av and Yom Kippur, at dawn.