"Maximum time period to display is 731 days." error

Hi,

When I'm in the legacy graph pages, and click "2 Years", I see the error message

```

Maximum time period to display is 731 days.

```

And the graph doesn't render. Sometimes I don't see the error, but the page still doesn't render. If I were to guess I would say that this is because this year is a leap year as I haven't seen this until very recently.

Is there a workaround, as I've got senior managers anxious to get two year graphing back for them? Related to my other open ticket with you, I'm guessing I could mess around with /usr/share/zabbix/include/defines.inc.php for now but I'll take any advice from you gratefully.