CalendarCast is a novel method to support the common task of finding a suitable time and date for a shared meeting among co-located participants using their personal mobile devices. We describe the Bluetooth-based wireless protocol and interaction concept on which CalendarCast is based, present a prototypical implementation with Android smartphones and dedicated beacons, and report on results of a user study demonstrating improved task performance compared to unaugmented calendars.

The motivating scenario for CalendarCast occurs quite often in a variety of contexts, for example at the end of a prior meeting or during ad-hoc conversations in the hallway. Despite a large variety of digital calendar tools, this situation still usually involves a lengthy manual comparison of free and busy time slots.

CalendarCast utilizes Bluetooth Low Energy (BTLE) advertisement broadcasts to share the required free/busy information with a limited, localized audience, on demand only, and without revealing detailed personal information. No prior knowledge about the other participants, such as email addresses or account names, is required.

A peer-reviewed conference publication about CalendarCast was presented at CHI 2016 ( A patent application was granted in late 2017, and was presented at the iENA International Research Fair in Nuremberg where it received a bronze award.