Pronunciation and definition/origin help please--

"Murk midnight" as above or generally.... is that usually pronounced "MURK-midNIGHT" with the last syllable accented where it's not usually ('MID-night' being the usual);

And does that time mean about 3-4 am-- halfway between midnight and dawn? As in the darkest hour is just before dawn?

Where/when's it originate?