Here we go, this works:
1.) Must have root. Use root explorer or ADB to move TouchWizCalendar.apk & .odex, TouchWizCalendarProvider.apk & .odex, and InfoAlarm.apk & .odex to somewhere on your SD Card as backups. Reboot.
2.) Go into manage applications. Filter to all. Uninstall com.android.calendar.apk and com.android.provider.calendar.apk. Reboot again
3.) Copy Calendar.apk and calendarprovider.apk from this thread across to your SD card. Install both.
4.) If you want, use root explorer to move them from /data/app to /system/app but really not necessary. Reboot again, should sync by default but re-enable if you need to.