Hi,
It seems that there is a bug in rich:calendar regarding week numbers.
Example: when yout display january of 2005 using gregorian calendar style (week starts with monday, first week of year has at least 4 days), you can see that last week od 2004 is 54. When you jump to december 2004, last week number changes to 53.
<rich:calendar
id="arrivalDate"
required="true"
value="#{newDelivery.arrivalDate}"
firstWeekDay="1"
minDaysInFirstWeek="4"
>
Hi,
This has been fixed recently, please try the latest 3.3.3-SNAPSHOT or wait until 3.3.3.CR1.