The Scheduler works with an idealized timezone that is based on UTC. It mean all dates need to be supplied without the timezone specification. If you specify the timezone it will be used to convert the data to UTC.
See also:
https://api.daypilot.org/daypilot-date-class/
If you need to make custom conversions you can pre-process the data source (the array with events) and convert the strings to DayPilot.Date objects as needed.