Must be the season of the moon! I changed my cutter yesterday. I always write on the old package when I changed the blade. The date of when I put in the new blade was August 8! I cut almost every day between trimming blocks and cutting fabric. I think perhaps 5 months might be too long to wait! Yikes! I must have been sawing the fabric for awhile! My husband says a dull knife can be as dangerous as a sharp knife when cutting. I think I'd better pay attention to this as it pertains to the rotary blades! Everyone, have a fun and safe day sewing!