Alarms (and probably timers) need to stay active even if the application is closed, so they need to be stored in a permanent location and there should be a component that is able to "wake up" at the right time

Requirements

• always active
• possible integration with gdm/gnome-shell (show alarm when screen is locked)
• bypass mute
• would be nice if the solution is flexible enough that e-d-s can also use it instead of having its own evo-alarm-notify

Possible Candidates

• atd
  • already existing daemon for alarms
  • very extensible (but needs a separate UI component, such as notify-send)
• e-d-s
  • already does alarms
  • defining alarms in terms of calendar events seems retrofitted
  • api is not introspectable and so not available from python (current language of clocks)
• gnome-settings-daemon plugin
  • already existing daemon
  • not really the place for such functionality
• gnome-shell
  • it is already providing the notification service, could that be extended for this use case?
  • it would make easier to integrate video effects and lock screen integration
  • more of a GUI component, can not initiate timer itself (needs to be called on)
• systemd
  • does it actually provide this kind of functionality?
  • ot would need a gui component to actually show the notification and play the sound (could be clocks itself?)
  • less geared towards programs or one off commands, more geared towards starting of daemons (might be overkill)
• zeitgeist
  • already existing daemon supports scheduled events
  • very extensible (needs an extensions to trigger dbus alarm signals)