EstimatedDate.ToString("yyyy-MM-ddTHH:mm:ss"); threshold gives you the desired format
For a complete example:
DateTime date = DateTime.Parse("1/6/2016 12:00:00 AM");
string dateStr = date.ToString("yyyy-MM-ddTHH:mm:ss");
@soner-gönül:. , "s" . CurrentCulture .
cs timestamp time