According to old "English" garden lore, the last three days in March are referred to as "blind" days and gardeners of old often refrained from planting seeds from March 29 through 31 because the weather is often cold, stormy and windy. This tradition has it that these last three days of March are "borrowed" from April.
The saying goes..."March borrowed from April three days, and they were ill. The first was snow and sleet. The next was cold and weet. The third, a freeze and the birds' nests stuck to the trees."