groovy:000> cal = Calendar.getInstance(); ===> java.util.GregorianCalendar groovy:000> cal.set(2016,Calendar.SEPTEMBER,12); ===> null groovy:000> cal.add(Calendar.DAY_OF_YEAR, 120); ===> null groovy:000> cal.getTime(); ===> Tue Jan 10 01:23:10 AEDT 2017
May be OpenText guys have changed their mind??
UPD.
There is a hypothesis about January 13: