Cron - Cron Calendar.
Priori - Curated legal marketplace for SMBs and startups
zcal - zcal is the fastest way to schedule every meeting for Free and make it personal.
Calendarist - Time blocking companion for Google Calendar
Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
Timo - Time and task management in your browser ⏲