Claire has mentioned in the past the buzzing being louder or less at different times of the year: in particular, the four seasonal solstices, and the four Gaelic festivals meant to celebrate them. She traveled on Beltane and Samhain. I believe Roger and Bree traveled at Beltane. We only know of our time travelers traveling on the cross-quarter days though it is possible they have traveled on quarter days.
Key Gaelic Festivals (Cross-Quarter Days)
- February 1/2: Imbolc (Candlemas)
- May 1: Beltane (May Day)
- August 1: Lughnashadh (Lammas)
- October 31/November 1: Samhain/Halloween
Quarter Days
- March 25: Lady Day
- June 24: Midsummer Day
- September 29: Michaelmas
- December 25: Christmas
