https://www.ibm.com/docs/en/db2-for-zos/13.0.0?topic=functions-fnmonth-from-datetime-function
Db2 13 - pureXML guide - fn:month-from-dateTime function
The fn:month-from-dateTime function returns the month component of an xs:dateTime value that is in its localized form.
purexmlguidefnmonthdatetime