agenda.app binary package in Ubuntu Focal arm64

 SimpleAgenda is a an application to manage your calendars. It
 handles both local and remote (webcal) calendars. Calendars can be
 shared with other programs like Evolution, Dates, IceApe Calendar and
 others. The following features are available:
 .
  * Multiple agendas.
  * Handle both events and tasks.
  * Support for local and remote (ftp, http) iCalendar agendas.
  * Monthly calendar, day view, summary and tasks view.
  * Create, resize and move appointments easily.
  * Export individual elements as files and to the pasteboard.
  * Import .ics files.
  * Simple text search.
  * Alarms with multiple backends.

Source package