Function skipDays

skipDays(
    calendar: SohlCalendarData,
    parts: DateParts,
    nDays: number,
): DateParts | null
Shift a date by a whole number of days, rolling months and years over correctly. Because a day is a constant number of seconds, this is exact arithmetic on the linear worldTime value — the calendar's own decomposition handles every month/year boundary (including variable-length months and intercalary days).
Parameters
- calendar: SohlCalendarData
  The active calendar.
- parts: DateParts
  The starting date parts (time of day is preserved).
- nDays: number
  Days to add (negative to go backward).
Returns DateParts | null
The shifted parts, or null if parts is not a valid date.
- Defined in src/core/logic/date-picker-logic.ts:121