Implementation of daterangepicker in controller

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C#

Javascript

MVC5

I already add a javascript code in view

<label>Time of generation:</label>
<input type="text" name="daterange" value=" " />
<script type="text/javascript">
$('input[name="daterange"]').daterangepicker();
</script>

and looks ok when i run application. Now I want to add search filter for the "insert_timestamp"

private IEnumerable<view_service> get_schedule_name(string sort_order, string searchString, string current_filter, Guid? Schedule_id)
{
Models.mbt_mainEntities db = new Models.mbt_mainEntities();



string sql = string.Format(@"select a.id as Schedule_id, a.code, a.insert_timestamp, b.name
from schedule.service a
left outer join schedule.calendar b
on a.calendar_id = b.id", Schedule_id);


IEnumerable<view_service> schedule_name = db.Database.SqlQuery<models.view_service>(sql).ToList();


// searching string filter
if (current_filter == null || current_filter == "_")
current_filter = "";

ViewBag.current_filter = current_filter;

// search string in schedule_name by bus_name and driver_name
if (!String.IsNullOrEmpty(current_filter))
schedule_name = schedule_name.Where
(s => s.code.ToUpper().Contains(current_filter.ToUpper()));


//sorting order by code, name, insert_timestamp

ViewBag.code = sort_order == "code" ? "code_desc" : "code";
ViewBag.name = sort_order == "name" ? "name_desc" : "name";
ViewBag.insert_timestamp = sort_order == "insert_timestamp" ? "insert_timestamp_desc" : "insert_timestamp";

ViewBag.current_sort = sort_order;


switch (sort_order)
{

How can I implement that?

What I have tried:

Tried to add same search string that alredy exists only with starDate end endDate but I thing I didn't set it right.