As plan for Noon and plan for Night — Romeo and Juliet

As plan for Noon and plan for Night ¹
So differ Life and Death
In positive Prospective－
The Foot upon the Earth

At Distance, and Achievement, strains,⁵
The Foot upon the Grave
Makes effort at Conclusion
Assisted faint, of Love.

(F.1075/J.960)

[1] plan for Noon:: plan of Romeo and Juliet's marriage in Friar Laurence' cell, noon of their love. plan for Noon:: plan of Romeo and Juliet's reunion, night of their love.
[2] differ Life and Death:: Marriage gives life; reunion gives death.
[3, 4] positive Prospective, Foot upon the Earth:: if their plan goes well, they can live together.
[5] At Distance:: far exiled Romeo shows his love.
[6] Foot upon the Grave:: the scene Romeo and Juliet die in the graveyard.
[8] Assisted faint:: Juliet's faint is assisted by Friar Laurence's medicine.

FRIAR LAURENCE.
Take thou this Vial being then in bed,
And this distilling liquor drink thou off, . . .
Shall stiff and stark, and cold appear like death,
And in this borrowed likeness of shrunk death
Thou shalt continue two and forty hours,
And then awake, as from a pleasant sleep.
─ Romeo and Juliet by Shakespeare

Why 42 hours? Forty sounds like faulty; "two and forty" alludes faulty two persons in this plan.