Steps to Reproduce

1. use -Duser.timezone=Europe/Berlin
2. date use for mat mm/dd/yyyy (non time)
3. at start datebox = empty
4. key in value 03/29/2500
5. debug at AuRequest class line 108 then value of sval = $z!t#d:2500.3.28.23.0.0.0 mean time offset at java script side for Europe/Berlin is GMT + 1
6. handle onChange event of DateBox class to get offset

Datebox dateBox = (Datebox)((InputEvent)event).getTarget();
LocalDateTime dateTime = dateBox.getValueInLocalDateTime();
	        
long offsetSecond = dateBox.getValueInZonedDateTime().getOffset().getTotalSeconds();
long offsetMiliSecond = TimeZone.getDefault().getOffset(dateBox.getValue().getTime());

Current Result

dateTime = 2500.3.29 01.0.0.0

offset get by both library = 720000 mili second

that value by 1 hour of zone offset and 1 hour of DST

Expected Result

dateTime = 2500.3.29 00.0.0.0

Debug Information

Workaround