// Return all last Sundays of each month in a given year
function* lastSundaysOfYear(year: number): Generator<Date> {
for (let month: number = 1; month <= 12; month++) {
// Last day of the month
let date: Date = new Date(year, month, 0); // day 0 of next month = last day of this month
// Walk backward to Sunday
while (date.getDay() !== 0) { // Sunday = 0
const d: number = date.getDate();
date = new Date(date.getFullYear(), date.getMonth(), d - 1);
}
yield new Date(date); // yield a copy
}
}
function main(): void {
const args: string[] = process.argv.slice(2);
const year: number =
args.length > 0
? parseInt(args[0], 10)
: 2026;
for (const date of lastSundaysOfYear(year)) {
const mm: string = String(date.getMonth() + 1).padStart(2, "0");
const dd: string = String(date.getDate()).padStart(2, "0");
const yyyy: number = date.getFullYear();
console.log(`${mm}/${dd}/${yyyy}`);
}
}
main();
/*
run:
01/25/2026
02/22/2026
03/29/2026
04/26/2026
05/31/2026
06/28/2026
07/26/2026
08/30/2026
09/27/2026
10/25/2026
11/29/2026
12/27/2026
*/
