How do I get the (date)timestamp since last cron run?

Question

I'm building a module but am stuck.. I need the timestamp from the previous cron as I run a hook_cron job so I can check which nodes are new and email those.

So I need the date/time stamp from the last cron run but how do I get there'?

Answer 1

A UNIX timestamp of the last cron run can be fetched with:

variable_get('cron_last');

If you need to, you can easily manipulate a UNIX timestamp with PHP's date function.

Answer 2

hook_requirement() function can help you.

Check this out: http://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_requirements/7

In your module file write hook_requirement() function.

function hook_requirements($phase) {
if ($phase == 'runtime') {
    $cron_last = variable_get('cron_last');

    if (is_numeric($cron_last)) {
      $requirements['cron']['value'] = $t('Last run !time ago', array('!time' => format_interval(REQUEST_TIME - $cron_last)));
    }
    else {
      $requirements['cron'] = array(
        'description' => $t('Cron has not run. It appears cron jobs have not been setup on your system. Check the help pages for <a href="@url">configuring cron jobs</a>.', array('@url' => 'http://drupal.org/cron')), 
        'severity' => REQUIREMENT_ERROR, 
        'value' => $t('Never run'),
      );
    }

    $requirements['cron']['description'] .= ' ' . $t('You can <a href="@cron">run cron manually</a>.', array('@cron' => url('admin/reports/status/run-cron')));

    $requirements['cron']['title'] = $t('Cron maintenance tasks');
  }
}