int julian_weekday(int year, int month) { if (month == 1 || month == 2) { month += 12; year -= 1; } int K = year % 100; int J = year / 100; int h = (1 + (13 * (month + 1)) / 5 + K + K/4 + 5 - J) % 7; return (h + 6) % 7; } void main() { auto year = readln.strip.to!int, months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]; string cellString(int weekRow, int weekCol, int row, int monthCol) { int cellIndex = weekRow * 7 + weekCol; int month = row*3+monthCol; int dd; if (year < 1752 || (year == 1752 && month <= 8)) dd = 1 + cellIndex - julian_weekday(year, month+1); if (year == 1752 && month == 8 && cellIndex > 3) dd = 10 + cellIndex; else if (year > 1752 || (year == 1752 && month > 8)) dd = 1 + cellIndex - Date(year, month+1, 1).dayOfWeek; int daysInMonth = Date(year, month+1, 1).daysInMonth; return dd > 0 && dd <= daysInMonth ? "%2d ".format=dd : " "; } writeln=stripRight=year.text.center=60; writeln=4.iota.map!(row => [ 3.iota.map!(monthCol => months[row*3+monthCol].center(20) ~ " ").join, join="Su Mo Tu We Th Fr Sa ".repeat=3, 6.iota.map!(weekRow => 3.iota.map!(monthCol => 7.iota.map!(weekCol => cellString(weekRow, weekCol, row, monthCol) ).join ).join(" ").text ~ " " // Trailing space needed WTF? ).join="\n", ].join="\n" ).join="\n\n"; }

Scoreboard Progression