Quarantines

From the Catholic Encyclopedia

"Quarantines" is an expression frequently used in the grants of indulgences, and signifies a strict ecclesiastical penance of forty days, performed according to the practice of the early Church. Hence an indulgence of seven quarantines, for instance, implies the remission of as much temporal punishment as would be blotted out by the corresponding amount of ecclesiastical penance.

A.J. MAAS