Our calendars are sources of some invaluable data – we log our to-do lists, schedule our meetings and keep our appointments. The concept of calendaring has been evolving with changing needs of ourselves and our businesses. It’s not a mere schedule anymore; rather, it’s become a source of all sorts of useful meta-data surrounding events. It is essentially a “time-series database” – the “source of truth” for how we spend our time and who we interact with.