dayOfYear

dayOfYear(date) → number · Date & Time

Return the day number within the year (1-365 or 1-366 for leap years).

• date (required): a date or datetime value

let d = parseDate("2026-05-01", "yyyy-MM-dd")
{
  ordinalDay: dayOfYear(d)          // 121 (121st day of 2026)
}

Also: daysInMonth(year, month) → daysInMonth(2026, 2) returns 28. daysInYear(year) → daysInYear(2024) returns 366 (leap year). isLeapYear(year).