Improve and modernize the Calendar design and usability

In Calendar, create a variety of events, including: events on the same day events at the same time on the same day events with different length (not just even hours or half hours) events on various days of the week Ensure you're able to create repeated events (e.g. frequency is weekly or daily or the same day of each month). Ensure you can change the calendar view (day, week, month, year, list) and that you're able to set different default views (so it starts with that default view when you reset the tool or log out and back in). Ensure the events appear on their correct day and time in all of the views (day, week, month, year, list). Ensure the Month view, a month in the Year view, and the month in the Overview > Calendar (the synoptic calendar) appear similar to one another and display the same events within the same site. Ensure you can merge internal and external calendars. Ensure you can subscribe to calendar events. Ensure you can add and remove custom fields. Ensure the wording on all of the pages is valid English, reads correctly (free of errors, typos, or grammatical issues), and makes sense. Ensure it is easy to navigate between events, days, and views using the calendar links.