The addYears method returns a new DayPilot.Date value with the specified number of years added.
DayPilot.Date.addYears(years)years (number) - number of years to add.
The current value is not changed. The method returns a new DayPilot.Date object.
const start = new DayPilot.Date("2025-03-01T00:00:00");
const result = start.addYears(1);