You can either use a string value (such as "2023-02-15" or "2023-02-15T00:00:00") which will be converted to an exact date.
const date = new DayPilot.Date("2023-02-15T00:00:00");
If you have a Date object and want to use its local representation when converting it to DayPilot.Date, you need to do it like this:
const now = new Date();
const date = new DayPilot.Date(now, true);
For more details on date conversions, please see here: