Sabbat
Day and night nearly level — a young festival wearing an old, borrowed, half-attested name.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
The event is exact and checkable: the sun crosses the celestial equator northward, between 19 and 21 March. Day and night come close to equal but not quite: sunrise is measured from the disc's first edge, and air bends light over the horizon, so the truly equal day falls a few days earlier at most latitudes. Southern-hemisphere practitioners keep this at the September equinox.
The name is the young part, and this is the place to be plain about the Wheel. Bede recorded an Old English month Ēosturmōnaþ and a goddess Ēostre in 725 — one paragraph, and the only mention of her anywhere. Jacob Grimm reconstructed a continental Ostara in 1835: inference, not attestation. Hares and eggs were attached later still. Modern pagans took the name for the equinox in the 1970s; the eight-fold Wheel it belongs to was assembled in the 1950s and 60s around Gerald Gardner and Ross Nichols.
So: the astronomy is ancient, the observance old, the name and the arrangement recent. Practitioners sow, weigh things up, and start what they mean to see through — no worse for knowing the label's age.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Bede, De temporum ratione (725)
Bede explains the English month names to a Latin-reading audience, and says in passing that Ēosturmōnaþ took its name from a goddess whose feasts were kept in it. That single remark is the entire early record. Everything built on top of it is later, and it is worth knowing which is which.
Carried forward
Jacob Grimm, Deutsche Mythologie (1835)
Grimm reasoned from Bede and from German month names to a goddess he called Ostara, and was clear that he was reconstructing rather than reporting. Later writers dropped the caveat. The name in common use today comes to us through that dropped caveat.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.