Festivals that are currently suggested are:

OSTARA - Festival of creation and new life - March 21st (Spring Equinox) (the Mithraic Easter)
LITHA - Summer Festival - (Summer Solstice)
MABON - Festival of harvest and celebration of the produce of life - September 22nd (Autumn Equinox)
MITHRAKANA - ('Festival of Mithras') - Celebration of religious life and religious community - 29th September
ATARKANA - ('Fire Festival') - Celebration of the free human spirit, the fire within - November 5th.
YALDA - Re-birth of the Sun
including: BRUMA (18th to 24th Dec)
when the Sun is at its weakest
and NOVUSSOL (25th Dec to 31st Dec)
when we celebrate the growing strength of the Sun