If you have a calendar linkage in Jicoo and the candidate dates are not blocked, first check to see if the "Calendar to check for appointments" is checked in the calendar linkage.
If there is no problem with the linkage,In order to block an appointment when arranging a date on Jicoo, you need to set your Google Calendar public settings to " Busy".
Please note that if you set "Free", the event will be displayed as a candidate and the appointment will be registered.
