String day = string.valueOf(system.now().day());
String month = string.valueOf(system.now().month());
String hour = string.valueOf(system.now().hour());
String minute = string.valueOf(system.now().minute());
String second = string.valueOf(system.now().second());
String year = string.valueOf(system.now().year());
String strTime = year+'-'+month+'-'+day+' '+hour+':'+minute+':'+second ;
system.debug(strTime);
system.debug(system.now());
output 1: 2015-7-7 14:5:55
output 2: 2015-07-07 08:35:55
================================================
Json.serialize()
to see underlying value irrespective of timezone