When Is Mabon 2024 Dates. Mabon occurs between the 21st and 24th of september, the exact opposite of the vernal equinox, to mark the beginning of spring, though in wiccan parlance it’s better known as ostara. In 2024, it's on september 22.

Mabon occurs in the the southern hemisphere on march 20, 2024, and on september 23, 2024 in the northern hemisphere. In 2024, this magical transition between summer.