I found my problem - I was trying to set the start date in my system default format of DD/MM/YYYY, while SnapCenter expects the American format of MM/DD/YYYY. Adding the following seems to have done the trick:
-Schedules @{'PolicyName'='03:30';'ScheduleType'='Daily';'StartTime'='07/27/2019 03:30 AM'},@{'PolicyName'='09:30';'ScheduleType'='Daily';'StartTime'='07/26/2019 09:30 AM'},@{'PolicyName'='15:30';'ScheduleType'='Daily';'StartTime'='07/26/2019 03:30 PM'},@{'PolicyName'='21:30';'ScheduleType'='Daily';'StartTime'='07/26/2019 09:30 PM'}One last thing that I can't quite figure out is where can I see the properties for this job? Aside from the resulting clones, it doesn't seem to show up anywhere in the GUI, and running "Get-SmCloneJob -PluginCode SMSQL -Resource @{'Host'='sql1.domain.local';'Type'='SQL Database';'Names'='SQL1\PROD\DB1'}" returns just CloneJobName and ResourceName. Am I missing something somewhere, or am I supposed to keep track of this separately from SnapCenter?