Summer Solstice takes place on June 21st and it marks the first day of summer. It is also known as Midsummer as this is when the sun reaches its peak, resulting in the warmest and longest day of sunlight of the year.
Beltane or May Day takes place on May 1st and is another cross-quarterly festival that marks the mid point between Spring Equinox and Summer Solstice.
Imbolc is a cross-quarterly festival that takes place on 2nd February in the Celtic calendar. It marks the half way point between Winter Solstice and the Spring Equinox. Also known as Candlemas, it is one of the fire festivals and a celebration of light.