What are calendar services?

Question

Calendar

Hello.
I rarely use calendars from Yandex and Google, but then it became necessary to make a calendar of holidays and events, regular I and G calendars are not suitable for all points.
Desired functionality:

• different display options: year, month, week, day;
  
• the ability to create a main event for the whole day and sub-events to it (for example, Victory Day as the main event and some separate events as sub-events by time or location);
  
• adding an image to the event (so that it is a preview in the monthly display;
  
• adding a location (by text or a pin in some map service);
  
• sharing the calendar with specific people or opening access to everyone;
  
• the ability to import and export events (albeit not perfect compatibility with other services, but at least basic data);
  
• the ability to insert a calendar on the site and view events without leaving it (site);
  
• the ability to edit the design;
  
• the ability to create groups of events (for example, public holidays, local holidays, historical events, etc.) with the ability to display individual groups.
  

Are there services that are most suitable for such conditions? In general, I will be grateful for any tips on good calendars, even if they do not satisfy all the wishes.