[SOLVED] Question about SaveObject()

Hello.
Mr babynus, first of all, I would like to thank you for your ongoing support. I appreciate if you help me with the following question:
Question1. I founded that SaveObject() is loaded when we click on save in pages such as Project, Document etc. I saw the source code but i could not recognize how i can get access to a scefic item (such as evaluated StartDate, Evaluated Enddate) which user has entered. for example the user enters date based on Jalali calander and when he clicks on save button i automatically change it to gerigorean calander format (However the user does not see the changed format). How can i get access to a specific item amout before being saved in SQL database?
Regards

As you mentioned, an object is made of the classes (presented in ../model) when we click save button. Then, we should refer to object and variable to access what a variable contains after clicking save. So in tool/saveObject.php i add this code, but an error occures. I appreciate to know your idea:
// first i added some codes for converting Jalali calendar to gregorian calander
if ( $classname == "ProjectPlanningElementMain") {
$newObj->validatedStartDate=date('Ymd', strtotime(jalali_to_gregorian(jdate('Y',$newObj->validatedStartDate),jdate('m',$newObj->validatedStartDate),jdate('d',$newObj->validatedStartDate),'-'))); //jalali_to_gregorian is a function which converts the date for example 1394-11-9 of jalali calander will be as 2016-1-29 and jdate is a related function
}
Thank you very much

Here it is