This cycle repeats every year and exacts on the specific degree of the Sun’s location in the zodiac.
Calendar dates change and exact time of day changes, but time is measure by SIGN & DEGREE OF THE SUN.
Theses moments go by various names although collectively they are called The Quarters & Cross Quarters of the Sun.
The Fall Equinox is sometimes called the Autumnal Equinox or as Mabon.
The Spring Equinox is alternatively referred to as the Vernal Equinox or as Ostara.
The Winter Solstice is sometimes called Mid–Winter or Yule.
The Summer Solstice is sometimes referred to as Mid–Summer or as Litha.
And the Cross Quarter of Lughnasad is referred to as Lammas in some traditions.