set date field of new record from current form date attribute using REST

Hi 

I have a web resource in a form that by clicking on a button inside that form, new record is created using REST. New records fields are filled from the form which contains the the web resource. Every thing is ok but date attributes. 

Say The form has field 'npDate' and I want to copy the exact value of that to new record field 'np_2_date'. It is being copied but with one day less than npDate. I log the value of 'npDate' to browser and it shows :

Thu Mar 20 2014 00:00:00 GMT+0430 (Iran Daylight Time)

but when I open newly created record form, I see that 'np_2_date' is one day less, like below:

Would you help me please ?