Carnival Thursday

Carnival Thursday

Between January 29 and March 4; Thursday before Shrove Tuesday
This is the day on which pre-Lenten celebrations, such as Carnival, traditionally begin, ending several days later on Shrove Tuesday night. These celebrations often take the form of wild revelry, which is perhaps why it also has been referred to as Mad Thursday .
SOURCES:
DictDays-1988, pp. 19, 72