Well, the feast of Corpus Christi is around 24th/25th March. Being part of Easter this feast could be a remnant of much older celebrations.

St. Brigit's Day is 1st February, the day before Imbolc. That's quite a discrepency datewise.

A good little page on St. Brigit here: http://www.irishclans.com/articles/famirish/stbrigit.html

One tale of St. Brigit's Cross tells of St. Brigit weaving a cross from reeds while attending a dying man. As she was brought up by a Druid was she doing a bit of magic and making an ancient talisman?