GNOME/Calendar

The Gnome calendar is the desktop calendar application built into GNOME.

Using Gnome Calendar outside of GNOME

To use the gnome calendar outside of gnome, you need the following lines in your configuration.nix:

{
  programs.dconf.enable = true;
  services.gnome.evolution-data-server.enable = true;
  # optional to use google/nextcloud calendar
  services.gnome.gnome-online-accounts.enable = true;
  # optional to use google/nextcloud calendar
  services.gnome.gnome-keyring.enable = true;
}

External calendar such as google/nextcloud can be only added via the gnome-control-center:

$ nix-shell -p gnome.gnome-control-center --run "gnome-control-center"

Than add your accounts in the "Online Accounts" submenu.

To get alarm reminder you need to start the evolution-alarm-notify deamon provided the gnome.evolution-data-server package. When you enable services.gnome.evolution-data-server.enable it will add a desktop autostart entry to /run/current-system/sw/etc/xdg/autostart/org.gnome.Evolution-alarm-notify.desktop. If your desktop manager does not process autostart entries, you can use dex instead:

$ dex --autostart

As an alternative you can start libexec/evolution-data-server/evolution-alarm-notify from the gnome.evolution-data-server directly.