Converting Date to ISO String in Schema Struct

export const Entry = S.Struct({
  itemType: ItemType,
  timePeriod: TimePeriod,
  date: // should be an ISO string,
  itemId: S.Int.pipe(S.nonNegative()),
})

export const Entry = S.Struct({
  itemType: ItemType,
  timePeriod: TimePeriod,
  date: // should be an ISO string,
  itemId: S.Int.pipe(S.nonNegative()),
})