filter pages by date field

[froot]

I'm building an event-calendar with php, ajax and js.

I want it to show a monthly overview when I click on a "month" button or when I switch the month. 
And show the events on one particular date when I pick a day. 
Also, most events are kind of exhibitions and so they have a start date and an end date much later, and occur on each day in-between as well.

So on the template I put two date picking fileds date_start and date_end. 

Is there an elegant way to select the events using the API? 

Because right now I'm pushing around and storing the pages (events) in arrays, looping through them a couple of times, using the AJAX-variables in if-statements to compare with. It kind of worked already but showing the events on the dates between start and end as well adds another level of difficulty and I wonder if so many loops would be scalable. 

I tried: 

$items = $page->children->filter('date("Ym", date_start)=$y.$m');

doesnt't work XD

Any advise?  

 

 

[Sergio]

You can filter by dates like so:

$events = $page->children('limit=50, date<=today, sort=-date');

Also check this thread to see more details:
 

date_start>=today
date_start>=1365436783
date_start>=2013-04-08
date_start>=4/8/2013
date_start>=8.4.2013
date_start>="April 8, 2013"