After traditional door hinges are used to mount a door, a door jamb lock is installed between the door edge and the door jamb. An upper wing is affixed to the door jamb. A lower wing is affixed to the door edge. An upper collar holds the upper wing and a central wing pivot pin. This central wing pivot pin can be pushed down to engage a female receiver in the lower collar and lower wing assembly. When this central wing pivot pin engages a key into the female receiver, the door is locked at a desired angle open. Various embodiments include a spring central wing pivot pin, a simple rod type central pivot pin, and a fine tuning set screw model for angle adjustment.