currently i m creating Visual web part , with SharePoint DateTimeControl trying to get select date from DateTimeControl programmatically .. how to get DateTimeControl selected date value.
You can get (or set) the selected value from code-behind (e.g. when user clicks a button) with
See https://karinebosch.wordpress.com/sharepoint-controls/datetimecontrol-control/ for examples (SharePoint 2007, but still relevant in 2013).
Example of sharepoint date time control if id= "DateTimeStartDate"
Then in the code behind .cs file you can access its value like below.
item["StartDate"] = Convert.ToDateTime(DateTimeStartDate.SelectedDate.ToString());