From page 15 of the SnapCenter Cmdlet Reference Guide (emphasis mine):
Schedules - Specifies in a hastable the schedule for the
clone job, including the policy name and the
schedule type. For example, -Schedules
@{"PolicyName"="BackupPolicy";"ScheduleType"="OneTime"}
You can specify multiple schedules in a comma separated list.
Here's the link to the guide, just for reference: https://library.netapp.com/ecm/ecm_get_file/ECMLP2840881
Donny