As commented, trying to access internally defined fields that were intentionally hidden from outside calling programmers would be unwise.
As commented, you seem to have an XY Problem. I'll take a stab at what you might need.
You are using terrible date-time classes that were years ago supplanted by the modern java.time classes defined in JSR 310. Never use Calendar, Date, etc.
You claim to have a call to a method requiring a java.util.Date object that represents the current moment as seen in UTC, that is, with an offset of zero hours-minutes-seconds. To capture the current moment, use Instant class.
Instant now = Instant.now() ; // Current moment as seen with an offset of zero.
I suggest you educate the author of that called method about how Date has been replaced by Instant.
Until they update their API, you can easily convert between legacy and modern classes by calling conversion methods added to the old classes.
java.util.Date d = Date.from( now ) ;
request.setGatewayEndTime( d );
As for the BaseCalendar.Date field, if your goal is to get a string in ISO 8601 format similar to the string you show in your screenshot which is nearly in standard format but omits the COLON from between the hours and minutes of the offset, then simply call Instant#toSting. The java.time classes use ISO 8601 format by default when parsing/generating strings.
String output = now.toString() ; // Generate text in standard ISO 8601 format.
Your screenshot uses another offset other than zero. If you wish to see a moment with the offset of a particular time zone, apply a ZoneID object to produce a ZonedDateTime object.
ZoneId z = ZoneId.of( "America/La_Paz" ) ;
ZonedDateTime zdt = now.atZone( z ) ;
Produce text in standard ISO 8601 format that has been wisely extended to include the name of the time zone in square brackets.
String output = zdt.toString() ;
cdatefield? That is an implementation detail that is intentionally not exposed to the end user. What kind of information do you hope to get from that? Generally speaking, you should try to avoid usingjava.util.Dataandjava.util.Calendarwhenever you can and use the modernjava.timeAPI instead.Dateobject in ISO-8601 format.DateandCalendar. Those classes are poorly designed and long outdated. Instead depending on your exact needs use for exampleOffsetDateTimefrom java.time, the modern Java date and time API.