The following functions are missing from the Date and Time Functions section of Appendix D "Extended Scalar Functions":
Note that WEEK_ISO() differs from the current definition of WEEK(), which returns a value up to 54. For the WEEK() function, Week 1 is the week containing the first Saturday. This is equivalent to the week containing Jan. 1, even if the week contains only one day.
DAYOFWEEK_ISO() and WEEK_ISO() are automatically available in a database created in Version 7. If a database was created prior to Version 7, these functions may not be available. To make DAYOFWEEK_ISO() and WEEK_ISO() functions available in such a database, use the db2updb system command. For more information about db2updb, see the "Command Reference" section in these Release Notes.