date format when getting a PDF document with RESTful changes

Hi all,

I have a simple document with a date concatenation (as a string) for DateFrom - DateTo (for example "1/4/2015 - 30/4/2015")

When I am in WebI I can see it in this format, even if I export it to PDF or Excel.

However when I open it using BO BI 4.1 SDK RESTful in PDF or Excel, the date changes to "American format" like this : "4/1/2015 - 4/30/2015"

Is there a way to avoid this, either as an option/parameter in the RESTful call or in the configuration of the BI server?

Thanks