How to Fetch and Show Calendar Overlay items usng Jquery or Rest or Sandbox ?

Hi,

I have Calendar items in Sitecollection and Subsites.

Using Calendar Over lay i am display all the subsites Calendar items in top level site collection.

But i am able to fetch the Site collection calendar items using knockout js and Rest api.I am not able to fetch the Calendar Over lay items in same code.

Please any body help me to achieve this using Rest API or knockout js or jquery or Sandbox.

Thanks in Advance

Mahesh