computus

Etymology
Borrowed from. .

Noun

 * 1) The calculation of the date of Easter in the Christian calendar.
 * 2)  A book of tables for calculating dates of astronomical events and moveable feasts.
 * 3) * 1987, Bruce Eastwood, 5: Plinian astronomical diagrams in the early Middle Ages, Edward Grant, John Emery Murdoch, Mathematics and Its Applications to Science and Natural Philosophy in the Middle Ages, page 149,
 * This computus also contains only one completed Plinian diagram, that for the planetary harmonic intervals.
 * 1)  A book of tables for calculating dates of astronomical events and moveable feasts.
 * 2) * 1987, Bruce Eastwood, 5: Plinian astronomical diagrams in the early Middle Ages, Edward Grant, John Emery Murdoch, Mathematics and Its Applications to Science and Natural Philosophy in the Middle Ages, page 149,
 * This computus also contains only one completed Plinian diagram, that for the planetary harmonic intervals.

Etymology
From.

Noun

 * 1)  computation, calculation
 * 2)  bank account