Borrowing Days

March 29 thru 31, the last three days of March, have a reputation for being stormy. Scottish folklore proposes that these three days were borrowed from April so that March might extend his power.

The Spanish story about the borrowing days is that a shepherd promised March a lamb if he would temper the winds to suit the shepherd’s flocks. But after his request was granted, the shepherd refused to deliver the payment. In revenge, March borrowed three days from April, in which fiercer winds than ever blew to punish the deceiver.

March borrowit from April
Three days, and they were ill:
The first was frost,
the second was snaw,
The third was cauld as ever’t could blaw.
~ Scottish proverb

From Almanac.com