Candlemas, celebrated on February 2nd, is traditionally regarded as the official end of Christmastide. This date falls forty days after Christmas and marks the Feast of the Presentation of Jesus in the Temple, as well as the Purification of Mary. It is also known for the blessing of candles, symbolizing Jesus as "a light for revelation to the nations," as stated in the Song of Simeon in the Bible (source).
Historically, some Christian cultures have extended the Christmas celebration to forty days, culminating on Candlemas. The tradition emphasizes the liturgical symbolism of Jesus' presentation and the light he brings to the world, thus bringing the Christmas and Epiphany seasons to a fitting close (source).
Candlemas is deeply rooted in Christian tradition as a significant liturgical feast that not only closes the Christmas season but also highlights themes of light, purification, and revelation (source).
Here is an image representing Candlemas: