HC-SR501 with LDR attached to it.

Yes. The added feature ( installing LDR inside the module) is doing exactly that.
What triggered this post was: How dark and how light the mcu will perform the disabling of the PIR function.
Also can I hack it to specific range of Darkness.

If anyone of you care to join me in this little hack, I can give you my thoughts on it.

The question is; is it worth it ?? For me it is the challenge.....there is no material benefits out of it.