public ClockViewModel() { //setup the preferences of the user. var dateFormat = ClockConfiguration.GetPreference(ClockConfiguration.Preferences.DateFormat); if (dateFormat == null) { dateFormat = DateFormats.First().Value; ClockConfiguration.SetPreference(ClockConfiguration.Preferences.DateFormat, dateFormat); } SelectedDateFormat = dateFormat; var timeFormat = ClockConfiguration.GetPreference(ClockConfiguration.Preferences.TimeFormat); if (timeFormat == null) { timeFormat = TimeFormats.First().Value; ClockConfiguration.SetPreference(ClockConfiguration.Preferences.TimeFormat, timeFormat); } SelectedTimeFormat = timeFormat; _timer = new DispatcherTimer(); _timer.Interval = new TimeSpan(0, 0, 1); _timer.Tick += timer_Tick; _timer.Start(); }