Hmm, save_actions uses a time and date extension anyway, not a random one.
By default Geany does not generate those files, so it must be some plugin or setting.
Try a completely default Geany by running `geany -c /tmp/non_existant` and see if it still generates those files.
If it doesn't then compare the settings and plugins with your normal ones to see what you have that is not default and causes it.