What Day Is Mardi Gras 2025. However, carnival celebrations always begin on january 6, a date referred to in the christian calendar as the twelfth night because it marks the end of the twelve days of christmas (and hence the holiday season). The official start of carnival season is twelfth night , january 6.
Here is the calendar of 2025 carnival parades. This date is crucial for many reasons, not least of which is that it marks the day before ash wednesday, which signals the start of lent in the christian calendar.