Scheduler Granularity is how frequneetly a job can run from the scheduler. By default, it is once every 15 minutes, and has been that way for many years, back to the old Omniback product
A few releases ago, there were some requests to increase the frequency that a backup job can run, so this was added to the 'global' file
# SchedulerGranularity=1 or 15
# default: 15
# This variable sets the scheduling granularity in minutes. Only
# values 1 and 15 are supported. Default value is 15 minutes.