WPF- TimePicker绑定以在运行时设置日期和时间

In my Wpf app, I've two TimePickers. I've used binding for them but their time is not updating. I also want to set selected date for these TimePickers.I tried to bind it as below. But, it won't work. Actual problem here is TimePickers are inside DataTemplate.In my Wpf app, I've two TimePickers. I've used