Imbolic is not just a Wiccan holiday but a pagan holiday. It marks the time when the crone becomes the maiden again as spring is on it's way. It is the first of the spring holidays or last of the winter depending on your perspective because it represents the change that it happening. It is the time of the lamb since this is when many of the spring lambs are starting to be born. The holiday dates back before christ and an exact date is hard to say since it was being celebrated before writing was common. It has many other names including but not limited to; Candlemas, St. Bridget's, and Groundhog's Day.
Celebrations include feasting on seeds. Anything that is made from seeds such as breads, toasted seeds such as sunflower or pumpkin, and even nuts. Also a ewe that did not bare a lamb is sacrificed for the feast. Activities include the lighting of candles in honor of the goddess and to light the rest of the dark days before Ostara, fire jumping, blessing seeds, making Bridget crosses, tuning over soil if you can, the planting of early spring plants' seeds, and dancing.