Fascinating word play and an interesting choice of subject.

An equinox occurs in spring and fall.

Day and night are roughly equal on these two days.

Just some of the sentences and phrases I will have to look up:

the azuring periphrase

the belled heaven claps the ground

strangered from every grave glissade

Light at Equinox

by Léonie Adams (1899 – 1998)

A realm is here of masquing light

When struck rent wood and cornland by

The belled heaven claps the ground.

Husk, seed, pale straw, pale ear the year reposes,

And a thinned frieze of earth rims round

The whey-gleamed wet-ash-dimming sky,

And whole trodden floor of light,

Where that slant limb winds with its shadowing closes.

Distant as lustrally the sun,
Within that pearl of nimble play
Where traverse with rehearsing tread
Orients of prime to their all-reaping west,
Strangered from every grave glissade
Of blue enduskings or of milky day,
And wan, his silver nimbus on,
Muses his burning sojourn unprofessed.

Past barks mouse-sleek, wattled as serpent skin,

Rare acorn fall, rare squirrel flash.

Beyond, and in a silenced scene,

The wren, gamin wanderer of immense day

Can with luxuriant bendings preen,

Or in his pebble-scoopings plash,

To alarmless Eden flown,

And suddenly, for nothing, flies away.

And all are sole in the estranging day;

Forms of all things their candour wear,

Like the undefending dead,

And forth from out that mortal stricture gaze,

Of unperspective radiance shed

Through everywhere horizoned air,

Tasking precising love to say,

For its dense words, the azuring periphrase.

To her own brink light glides, intent

An unsphering sense to bind

By narrowing measures in.

Sidelong as then up branching March she bade

Stiff buds into the glancing skein,

And the green reel unwind;

Now toward another pole she’s leant,

And netherwards for partner draws her shade.