isWeekday

isWeekday(date) → boolean · Date & Time

Returns true if the date falls on a weekday (Monday through Friday).

• date (required): date or datetime

isWeekday(parseDate("2026-05-01", "yyyy-MM-dd"))  // true (Thursday)

// Use case: calculate business days
let startDate = parseDate($input.start, "yyyy-MM-dd")
let workDays = filter(
  map(range(0, 30), (i) -> addDays(startDate, i)),
  (d) -> isWeekday(d)
)
{ businessDays: count(workDays) }