Indulgences were always either partial or plenary. Partial endulgence = indulgence of X many days. The church has stopped announcing days on partial indulgences because they were creating scandal for the faithful. Too many people were believing that “300 days” meant 300 days knocked of purgatory, as opposed to 300 days penance in accordance with ancient norms for confession. Basically, the length of days has lost all meaning now, except if one wanted to compare which prayer they wanted to say based on which indulgence was longer, which in my opinion, is another abuse.
Josh
