duration.js

function duration (dat) {
	var ret = 0, map = {
		sec:1, min:60, hour:3600, day:86400, week:604800, month:2592000, year:31536000
	};
	for (var k in dat) if (map[k]) ret += dat[k] * map[k];
	return ret * 1000;
}

/*
function eq (obj, expect) {
	if (obj == expect) {
		print("ok\n");
	} else {
		print("ng\nexpect:\n" + uneval(expect) + "\nbut:\n" + uneval(obj) + "\n");
	}
};

eq(duration({sec:1}), 1000);
eq(duration({min:1}), 60 * 1000);
eq(duration({hour:1}), 60 * 60 * 1000);
eq(duration({day:1}), 24 * 60 * 60 * 1000);
eq(duration({week:1}), 7 * 24 * 60 * 60 * 1000);
eq(duration({month:1}), 30 * 24 * 60 * 60 * 1000);
eq(duration({year:1}), 365 * 24 * 60 * 60 * 1000);
eq(duration({day:1, hour:12}), (24 * 60 * 60 + 12 * 60 * 60) * 1000);
*/