Write a program or a script that returns the last Sundays of each month of a given year. The year may be given through any simple input method in your language (command line, std in, etc).

Example of an expected output:

./last_sundays 2013
2013-01-27
2013-02-24
2013-03-31
2013-04-28
2013-05-26
2013-06-30
2013-07-28
2013-08-25
2013-09-29
2013-10-27
2013-11-24
2013-12-29


Related tasks
 Day of the week
 Five weekends
 Last Friday of each month


import os, strutils, times
 
const
  DaysInMonth: array[Month, int] = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
  DayDiffs:  array[WeekDay, int] = [1, 2, 3, 4, 5, 6, 0]
 
let year = paramStr(1).parseInt
 
for month in mJan..mDec:
  var lastDay = DaysInMonth[month]
  if month == mFeb and year.isLeapYear: lastDay = 29
  var date = initDateTime(lastDay, month, year, 0, 0, 0)
  date = date - days(DayDiffs[date.weekday])
  echo date.format("yyyy-MM-dd")