Help me to understand this poem please

Hey, can anyone help me to understand this poem please? it's for Emily Dickmon and its named "if you were coming in the fall"
these are the lines:.....
"""""""""""""""""""""""""""""""""""""""""""""""""""""""
If you were coming in the Fall
I'd brush the summer by
With half a smile and half a spurn
As Houswives do, a Fly

If i could see you in a year
I'd wind the months in balls
And put them each in separate Drawers,
For fear the numbers fuse

If only Centuries delayed
I'd count them on my hand
Subtracting till my fingers dropped
Into Van dieman's Land

If certain, when this life was out
That yours mine, should be
I'd toss it yonder, like a Rind,
And take Eternity

But, now, uncertain of the lenght
Of this, that is between,
It goads me, like the Goblin Bee
That will not state its sting
"""""""""""""""""""""""""""""""""""""""""""""""""""

since i am an inexpert poet and english is not my first language i found difficulty to understand the poem. also some words were hard for me to translate it and then relate it to the poem.
i need your help please

thanks in advance

Hey thanks alot for this explanation...it makes more sense to me now