プロ生のアレ

calendar.d

import std.stdio    : write, writef, writeln;
import std.datetime : Clock, Date;
import std.conv     : to;

void main() {
	auto t = Clock.currTime();
	auto count = t.endOfMonth.day;
	auto offset = new Date(t.year, t.month, 1).dayOfWeek.to!int;

	foreach (i; 0 .. offset) {
		write("   ");
	}
	foreach (i; 1 .. count + 1) {
		writef("%2d", i);
		write((i + offset) % 7 == 0 ? "\n" : " ");
	}
	writeln("");
}