Observing time on the Keck 10-m telescopes is available to members of several communities: The University of California (UC), The California Institute of Technology (Caltech), the National Aeronautics and Space Administration (NASA), the University of Hawaii (UH), Yale University, the Subaru (NAOJ) community through an observatory exchange, the National Optical Astronomy Observatory (NOAO) through the NSF's Telescope System Instrumentation Program (TSIP), and the Gemini community* through an observatory exchange.
Each community has its own Time Allocation Committee (TAC) that reviews proposals semi-annually and assigns time based on the scientific merit of each proposal. Those time assignments are then used to generate the night-by-night schedule for each of the telescopes.
Observing time on the Keck telescopes is not available to the general public.
* not currently available.