Old conjurer.

Old Style (O.S.) and New Style (N.S.) indicate dating systems before and after a calendar change, respectively. Usually, they refer to the change from the Julian calendar to the Gregorian calendar as enacted in various European countries between 1582 and 1923. Before as well as after the legal change, writers used the dual dating convention to specify a given day by giving its date according to both styles of dating (to ensure that the day concerned was identified unambiguously). In England, Wa…