Version: 1.1 (using KDE 4.5.5) OS: Linux The "special dates" item no appears even between the Extensions in Settings / Configure summery View. Until yesterday, the item was present. Reproducible: Always OS: Linux (i686) release 2.6.37-CHAKRA Compiler: gcc
Assuming you're using kdepim 4.4.10, that's on purpose. See http://commits.kde.org/ee6cc38b/cb87362163afbed2dca419c839c342a7b5ec675f for the details and how to reenable it at build time.