Mariah Carey on stage in 2017Mariah Carey wasted absolutely no time in telling everyone that the moment to start getting in the festive mood has officially arrived.At one minute past midnight the day after Halloween, the All I Want For Christmas Is You singer kept up her yearly tradition of posting an elaborate video on social media, all with the intention of letting everyone know that “it’s time”.This year’s video begins with Mariah channelling the legendary character Morticia Addams, Tango-ing around a spooky mansion in full costume to what we can only describe as a Strictly-fied version of her iconic festive hit.At the end of the video, Mariah pulls a lever that turns the celebrations from Halloween to Christmas, with even her Tango partner being transformed from Gomez Addams into a happy snowma