Question

I’m trying to write a calendar function like this

function get_date($month, $year, $week, $day, $direction)
{
    ....
}

$week is a an integer (1, 2, 3…), $day is a day (Sun, Mon, …) or number, whichever is easier. The direction is a little confusing, because it does a different calculation.

For an example, let’s call

get_date(5, 2009, 1, 'Sun', 'forward');

It uses the default, and gets the first Sunday in May ie 2009-05-03. If we call

get_date(5, 2009, 2, 'Sun', 'backward');

, it returns the second last Sunday in May ie 2009-05-24.

Answer 1

Perhaps it can be made quicker…
This was VERY interesting to code.

Please note that $direction is 1 for forward and -1 for backward to ease things up 🙂
Also, $day begins with a value of 1 for Monday and ends at 7 for Sunday.

function get_date($month, $year, $week, $day, $direction) {
  if($direction > 0)
    $startday = 1;
  else
    $startday = date('t', mktime(0, 0, 0, $month, 1, $year));

  $start = mktime(0, 0, 0, $month, $startday, $year);
  $weekday = date('N', $start);

  if($direction * $day >= $direction * $weekday)
    $offset = -$direction * 7;
  else
    $offset = 0;

  $offset += $direction * ($week * 7) + ($day - $weekday);
  return mktime(0, 0, 0, $month, $startday + $offset, $year);
}

I’ve tested it with a few examples and seems to work always, be sure to double-check it though 😉