I intend to orphan the gsimplecal package.

The package description is:
 gsimplecal is a lightweight calendar application written in C++
 using GTK3.
 .
 It was intentionally made for use with tint2 panel in the openbox
 environment to be launched upon clock click, but can be bound to
 some hotkey in any window manager.
 .
 gsimplecal can be configured to not only show the calendar, but
 also display multiple clocks for different world timezones.