first of all your submitting datetime should include .Date Keyword it makes your time to 1200 or 0000000
like that
ent.Receiving_Date = dateTimePicker1.Value.Date;
In database it will look like that
2020-04-01 00:00:00.000
Now you are going to Search or filter the data on the base of date then you will also give .Date here with datetimePicker as given below ;
var dd=db.tbl_Doner.Where(x => x.Receiving_Date==dateTimePicker1.Value.Date).ToList();
dataGridView1.DataSource = dd;
I hope it will work
I have got it about half an hour before posting to you, after spending alot of time on it.During search I found above answers but not working in first approach of EF.so best of Luck