Not Lost in Translation

(4)

I questioned Lucifer about Omar Khayyam. Seems he lived in the eleventh(?) century. He was a Persian poet, mathematician, and astronomer, and was instrumental in refining the calendar. Lucifer advised me that Omar liked to speak in verses which were somewhat obscure and warned me that I should employ the services of a translator. He suggested himself for that job.
I accepted.

om:
There was the Door to which I found no Key;
There was the Veil through I might not see;
Some little talk of Me and Thee
There was - and then no more of Thee and Me.
(translation: Welcome to my world.)
me: They tell me you are a mathematician who refined the calander.
om:
Ah, but my Computations, People say,
Reduced the Year to better reckoning? - Nay,
'Twas only striking from the Calendar
Unborn Tomorrow, and dead Yesterday.
(translation: That is correct.)