Queue Mode Software for Subaru Telescope

Subaru Telescope has operated under a classically-scheduled regimen since starting open use in Y2000. However, from semester 16A onward Subaru is transitioning to queue scheduling for the Hyper Suprime-Cam instrument and has plans to operate future instruments also in queue mode. Subaru carefully studied the queue operation at Gemini, JAC and CFHT before settling on a model for Subaru. In this paper we discuss the queue workflow, the type of scheduling used by the observatory, the changes and choices for the queue software layer, which was developed using open source packages and in the Python language.