import Foundation
// Return all last Fridays of each month in a given year
func lastFridaysOfYear(_ year: Int) -> AnySequence<Date> {
let calendar = Calendar(identifier: .gregorian)
return AnySequence<Date> {
var month = 1
return AnyIterator<Date> { // <-- FIX: specify <Date>
guard month <= 12 else { return nil }
// Last day of the month
let comps = DateComponents(year: year, month: month + 1, day: 0)
var date = calendar.date(from: comps)!
// Walk backward to Friday
while calendar.component(.weekday, from: date) != 6 { // Friday = 6
date = calendar.date(byAdding: .day, value: -1, to: date)!
}
month += 1
return date
}
}
}
let args = CommandLine.arguments
let year: Int =
args.count > 1
? Int(args[1]) ?? 2026
: 2026
let formatter = DateFormatter()
formatter.dateFormat = "MM/dd/yyyy"
for date in lastFridaysOfYear(year) {
print(formatter.string(from: date))
}
/*
run:
01/30/2026
02/27/2026
03/27/2026
04/24/2026
05/29/2026
06/26/2026
07/31/2026
08/28/2026
09/25/2026
10/30/2026
11/27/2026
12/25/2026
*/
/*
run:
01/30/2026
02/27/2026
03/27/2026
04/24/2026
05/29/2026
06/26/2026
07/31/2026
08/28/2026
09/25/2026
10/30/2026
11/27/2026
12/25/2026
*/
