Calendar

Detailed description of each events

You can enter simple dates for meeting etc but then you can add things like a date of birth and make it recur annually so that you get reminders that include how old a person is. When you add dates for flights you can enter the departure and arrival times and set the relevant airports so it works out local t...

Keep it simple, use Google !

Easy to use and great display so you can see all plans by just overlooking it

The only native solution I know of for MacOS and iOS that offers both full-fledged calendar and task management.