I want to know the answer to the following question:
What did mathematicians of the time want to use to set the date of Easter?
All the background I'm provided with is that "The Council of Trent approved a plan in 1563 for correcting the calendrical errors, requiring that the date of the vernal equinox be restored to that which it held at the time of the First Council of Nicaea in 325 and that an alteration to the calendar be designed to prevent future drift.". Is that enough to answer the question?