Convert timezone value from seconds to WC3 hour format

Question

Doing an API integration that requires timezones to be handed off in W3C format, while Drupal opts to store timezones in seconds.

Wondering what the clean way to do this is, rather than stripping the +/- sign, dividing by 3600 and adding it back on. There has to be a date transformation right?

FYI... W3C looks like this: -08:00 and Drupal looks like this: -28800

Trying to avoid this code...

// $val = '-28800';
$sec = substr($val, 1);
$hours = intval(intval($sec) / 3600);
$minutes = intval(($sec / 60) % 60);
$w3cTZ = substr($val, 0, 1) .
  str_pad($hours, 2, "0", STR_PAD_LEFT) .":".
  str_pad($minutes, 2, "0", STR_PAD_LEFT);

Answer 1

Ended up this this function...

// Convert timezone from second in Drupal to WC3 standard
function timezoneConvert($val, $toSeconds = false) {
  if(!$toSeconds) {
    // Starts like: "-28800" and becomes: "-08:00"
    $sec = substr($val, 1);
    $hours = intval(intval($sec) / 3600);
    $minutes = intval(($sec / 60) % 60);
    $w3cTZ = substr($val, 0, 1) .
      str_pad($hours, 2, "0", STR_PAD_LEFT) .":".
      str_pad($minutes, 2, "0", STR_PAD_LEFT);
    return $w3cTZ;
  }
  else {
    $seconds = 0;
    $units = explode(':',$val,2);
    $seconds += $units[0] * 3600; // Hours
    $seconds += $units[1] * 60; // Minutes
    return $seconds;
  }
}