Remove 'Update Blog Settings' notification

How can we remove the notification;
“Ajax Event Calendar requires a city value for the Timezone setting.
Not all cities are listed. Can’t find your city in the timezone dropdown?… Search for your standardized timezone..
Update Blog Settings”

Have updated blog settings, time date format etc, but the notification remains.

http://wordpress.org/support/plugin/ajax-event-calendar

http://wordpress.org/extend/plugins/ajax-event-calendar/