Some people like to celebrate 22nd April as Yggdrasil Day. This is not a historically attested festival, but is something from the modern "neo-Heathen" path. It is a day when some modern Heathens contemplate their place within the nine worlds, and the special blessings that nature gives to us. Some like to celebrate by planting a tree, or by making a libation to an ash tree. So if you celebrate Yggdrasil Day, I wish you blessings this day to you and your kin!