Cron deletes all visits

@manicato - By default, last 7 days visitor data is saved. So it's not a bug and user can configure it from the admin section.

Please goto Configuration->User visits (admin/config/people/user_visits) and configure it as per your needs.

This is also happening for me. I have the module configured to save 365 days of data and yet every time cron runs it clears all of the visitor data.

Looking at user_visits_adv.module row 242-245, I believe this is the source of the deleted data some people are seeing.

<?php
      // Store all data.
      db_update('user_visits_adv')
        ->fields(array(
        'total' => total + $visit->count,
        'visitors' => serialize($visit->recent_visitors),
        'history' => serialize($history),
        ))
        ->condition('uid', $visit->uid)
        ->execute();
?>

Specifically this row where "total" is not a variable nor a constant:

<?php
        'total' => total + $visit->count,
?>

Added patch to fix this problem to Issue 2375133: Notice: Undefined offset: in user_visits_adv_cron() (line 216 of user_visits_adv.module