Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
Qloapps - Open Source System - Build Hotel Booking Website and Manage Online & On-Desk Bookings.
Etar - Material design open source calendar for Android.
FewohBee - Web based management tool for hotels, pensions, accommodations and vacation homes
Google Calendar - Spend less time managing your day & more time enjoying it
BSI Hotel Booking System - BSI Hotel Booking System is a real time online hotel booking.