Clean Monday is the first day of Great Lent in Eastern Orthodox Christianity. It marks the beginning of a 40-day period of fasting and repentance leading up to Easter. The day is significant for its focus on spiritual cleansing, renewal, and preparation for the resurrection of Christ.

Shrove Monday is part of the Christian pre-Lenten period known as Shrovetide. While less well-known than Shrove Tuesday, it historically held significance in certain Christian traditions, especially in Europe and the UK.