Spring Equinox 2025 Uk Calendar. Find london march and september equinox, june and december. Ostara, celebrated around the time of the spring equinox between march 20th and 23rd, marks a period of rebirth and renewal, capturing the essence of spring's arrival.

The first day of spring (march equinox or vernal equinox) is when the sun shines directly on the celestial equator passing from south to north and the length of day and night. On this date, the day is equal.