Calendly - Say goodbye to phone and email tag for finding the perfect meeting time with Calendly. It's 100% free, super easy to use and you'll love our customer service.
Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
Dotcal - Personalized booking pages for absolutely everyone
Cron - Cron Calendar.
Easy! Appointments - Open Source Appointment Scheduler
Planist - Schedule meetings in an easy way Planist can connect with your google calendar to automatically check availability and help you connect with your best contacts, prospects, and clients.