Showing datepicker in Itemcontrol in wpf - wpf

Question

I am using Itemscontrol with wrappanel being used as ItempanelTemplate. The ItemTemplate using datatemplate containg of combobox.
The combobox contains list of items and when "custom" option is choosen I need to change the combobox control to show start date and end date fields to choose date from calender. The other comboboxes should remain intact.
MainWindow.xaml
<Window x:Class="ICExample.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:ICExample" xmlns:system="clr-namespace:System;assembly=mscorlib"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<ItemsControl ItemsSource="{Binding}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding TimeFrame}" Margin="0,0,5,5" Width="90" Height="60" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
</Window>
MainWindox.xaml.cs
public partial class MainWindow : Window
{
List<Person> personList = new List<Person>();
public MainWindow()
{
InitializeComponent();
Populate();
DataContext = this.personList;
}
private void Populate()
{
personList.Add(new Person() { TimeFrame = { "1 month", "1 day", "1 year", "custom" } });
personList.Add(new Person() { TimeFrame = { "1 month", "1 day", "1 year", "custom" } });
personList.Add(new Person() { TimeFrame = { "1 month", "1 day", "1 year", "custom" } });
personList.Add(new Person() { TimeFrame = { "1 month", "1 day", "1 year", "custom" } });
}
}
public class Person
{
private List<string> _timeFrame = new List<string>();
public List<string> TimeFrame
{
get
{
return _timeFrame;
}
set
{
_timeFrame = value;
}
}
}