Desktop Appearance 'Changes Throughout The Day' Option Not Working

Hello,

I'm running Trisquel 6.0 32bit with Gnome and discovered a minor issue here:

Trisquel Start Icon> System Settings> Appearance:

The option to have the deskop appearance change throughout the day doesn't seem to work. I've tested it out for a while now and it never changes. I believe this issue was also in Trisquel 5.5 with Gnome too.

Not a major problem I know, I just thought it should be made a aware of.