An interactive terminal timer / alarm clock. Asks whether you want a countdown timer or an alarm at a clock time, waits with a live countdown, then rings until you press Ctrl-C.
One might find it convenient to launch it with such Bash funtion:
alarm ()
{
local s=$(date +%H%M%S);
kitty --detach --class "alarm-$s" "$HOME/my-software/Python/clock/clock.py"
}