When setting up an HPC Location on the Setup screen, there is an optional 'Active Date' field available. This can be used to effectively hide this location on the HPC screen until the active date and thereafter. An example use case is...you have a new location, but you don't want anyone selecting this location on the HPC screen until a date in the future. But, you want to be able to establish a schedule for this new location on the Scheduler.
Note: leaving the Active Date field blank will give access to this location on the HPC screen indefinitely.