java - parse a date from string gives exception in android -

i want parse string string date ,date of format tuesday march 19,2015. want parse , format yyyy-dd-mm format. below code gives me exception "unparceble date".

code :

dateformat df1 = new simpledateformat("yyyy-mm-dd"); try {     date1 = df1.parse(currentdate);     system.out             .println("============my formated date====================" + date1.tostring());     calendar cal = calendar.getinstance();     cal.settime(date1);     cal.add(calendar.date, 10); // add 10 days      date1 = cal.gettime();      system.out.println("==============added date==============" + date1.tostring()); 

i have created 1 common function convert date format. have pass old date format, new date format , date.

public static string convertdateformat(string oldformat, string newformat, string inputdate)     {         dateformat thedateformat = new simpledateformat(oldformat);         date date = null;          try         {             date = thedateformat.parse(inputdate);         }         catch (parseexception parseexception)         {             // date invalid. want.         }         catch (exception exception)         {             // generic catch. want.         }          thedateformat = new simpledateformat(newformat);         return thedateformat.format(date).tostring();     } 

// call funcation

string converteddate = convertdateformat("eeee mmm dd,yyyy","yyyy-mm-dd",datetoconvert);