Start handshake/time diff: https://git.panter.ch/rmo/jdrums/blob/3153d333826397efd9c95259f52f632ba7a1071f/public/client.js#L19 Adding diff to calc: https://git.panter.ch/rmo/jdrums/blob/3153d333826397efd9c95259f52f632ba7a1071f/public/client.js#L224