Planzer.io offers Free Trial, but Calendar does not.
Planzer.io is designed for Large Enterprises, Medium Business and Small Business.
Calendar is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for Planzer.io Starts at $10/Month whereas for Calendar Starts at $6/Month when Billed Yearly.
Some top alternatives to Planzer.io includes Week Plan, Office Tracker, Social Tables, SoPlan, ToEvent, Groupize, WeekToDo, Atomicly, Calendar and Calendarist.
Some top alternatives to Calendar includes Appointy, Calendly, Cogsworth, Scedule, OpusTime, Book Like A Boss, Calendar.AI, EasyCalendar, Hupport, Office Tracker, Schedule it, Schedule.cc by 500apps and DaySchedule.