The Autumnal Equinox or Mabon is one of the four main quarterly festivals in the Wheel of the Year (Pagan calendar). It takes place around the 21st/22nd September and marks the second of three harvest festivals, the other two being Lammas and Samhain. This is known as the first day of Autumn.
Lammas is all about abundance and giving thanks for the harvest. This Celtic sabbat celebrates the Goddess as the Grain Mother and the Sun God who sacrifices his life so that the harvest can be cut and gathered.