The calendar format makes the effect virtually impossible to measure: it should be a constant, year-round, slow-burn rather than a discernable sales or awareness spike.We do know that we’ve struggled to meet calendar demands from the trade because they’re so chuffed by it. We do know they’ve gone down a storm at cash ‘n’ carries, which is crucial for distribution. We also know it’s helped spark pub chats, which ensures the brand’s kept at the top of our audience’s minds – and is probably thought about every three seconds…