Festival of the Lost made sense. The other ones do not. If they have any other events that are near holidays they should be Destiny specific. Example: -New Years could stay New Years. Celebrating surviving the Darkness another year. -The winter season could be the Celebration of the Light. Though I would probably make this sometime in the spring and just let New Years even run though the end of December into January. -You could definitely have some fun with Valentines Day. Something fire team related. -Maybe have a day of Mourning for the Traveler. I'm sure there is a holiday for this somewhere.