How to split db result with date values into single day groups

[eluser]LuckyFella73[/eluser]
Hello,

I have a db table having date entries. I need to get all
entries and when looping through the result_array I
have to group the entries by day.

My task is to build HTML list items where I have all rows
of one day in one list item.

Code:

<ul>
<li>
  All rows having DB date 2012-08-12
</li>
<li>
  All rows having DB date 2012-08-13
</li>
<li>
  All rows having DB date 2012-08-14
</li>
<li>
  etc.
</li>
</ul>

It may be easy but I have no idea how to do that ...