Abstract: Disclosed is a calendar service which operates on multiple devices, including mobile devices and personal computers, which works with a server which can update or synchronize calendars across multiple 3rd party calendar servers, which can change the amount of calendar data displayed depending on the zoom level of the display, which facilitates display of weekend days together, which can display a 2×2 grid of two days (horizontally) across two successive weeks (vertically), which 2×2 grid can be shifted up or down to traverse weeks or right or left to traverse days, which enables family members to quickly find and communicate free time, and which can display days in a week with a continuous vertical scroll.