Starting from S18A it is possible to propose programs that are time critical. From S19B these are offered to Normal, Intensive and Filler Program. The PI should provide sufficient information about when the observations are supposed to be carried out, i.e. define certain time windows, as part of the Phase 1 submission. Please note, however, that the exact allocation of queue nights is not defined until Phase 2. To increase the possibility of execution of the program, the PI should specify the time windows as relaxed as possible. We'd like to remind that, usually, each HSC observing run lasts for ten days or longer during the dark and gray nights.
So-called cadence programs (observations taken regularly every certain amount of time) are allowed in a restrictive sense starting from S18B, in the form of shared-risk mode monitoring proposals. Details are provided in Section 2.1.2.