Google Calendar - Spend less time managing your day & more time enjoying it
Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Standard Notes - A safe place for your notes, thoughts, and life's work
iCal - In Calendar on your Mac, subscribe to calendars published or shared by others.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.