Pan's Anniversary, or The Shepherd's Holiday was a Jacobean era masque, written by Ben Jonson and designed by Inigo Jones. The date of the masque's performance at the English Court has long been in dispute: while the earliest text assigns it to 1625, mid-twentieth-century scholars placed it on 19 June 1620, the king's birthday, at the royal palace at Greenwich. More recently, Martin Butler has argued for a date of 6 January 1621. Source: Wikipedia (en)