Associate calendar with left-click on Clock

[PePa]

Nick Schermer <nick <at> xfce.org> writes:
> There is a hidden option you can set to spawn a command when double
clicking the clock (since 4.10). Add a "command" text property to the clock
plugin config in the panel channel with the settings editor. The text value
you set will be launched.
> Nick
> 
> On Mon, Jan 13, 2014 at 1:37 PM, Jerry Bond <stormyjerry <at> gmail.com>
wrote:
>     There is no apparent left-click action associated with Clock, and I
>     am wondering if that click event could be bound to the tiny gsimplecal
>     (https://github.com/dmedvinsky/gsimplecal).  That developer says it
>     was created precisely for use with a clock, and his home page makes
>     it sound like he is very accessible.

I would love a more fuller integration of the excellent gsimplecal into
XFCE, but this is a good start. Is there also a hidden option to respond to
a single left-click? That would be even better.
XFCE lacks a good worldclock (I find Orage Globaltime horrible).