[Mediawiki-l] Auto Updating Issue

[mrthetooth]

So I'm trying to make an "Image of the Day" template, but I'm having trouble with the image changing automatically each day.

I created a page (for example, Screenshot) with a subpage for every day (for example, Screenshot/October 6, Screenshot/October 7, Screenshot/October 8).  On each of these subpages I display one image.   The template transcludes a subpage depending on the day.  Here is essentially the code:

{{#ifexist:  Screenshot/{{#time: F j}} | {{: Screenshot /{{#time: F j}}}} | {{: Screenshot /default}} }}

This works well sometimes.  Some days the image that the template displays changes on its own when the date changes.  Other days I have to manually click "edit" and then "Save page" in order to refresh the image.

I essentially have two questions:

1.       Why does this template work inconsistently; i.e., some days images changes on its own, and some days not?

2.       How can I make the image always change on its own?