date time SQL SERVER database datetime.parse comparison ASP.NET C#

if (!String.IsNullOrEmpty(dt.Rows[0]["Course_EntryOn"].ToString()))

                {

if(Convert.ToDateTime(dt.Rows[0]["Course_EntryOn"].ToString(), System.Globalization.CultureInfo.InvariantCulture)<= DateTime.ParseExact("2022-04-01", "yyyy-MM-dd", System.Globalization.CultureInfo.InvariantCulture) )

}

or

 new SqlParameter("@START_DATE",txtFrom.Text!=""? DateTime.ParseExact(txtFrom.Text,"dd/MM/yyyy",System.Globalization.CultureInfo.InvariantCulture).ToString("MM/dd/yyyy"):null)

if(DateTime.ParseExact(dt.Rows[0]["Course_EntryOn"].ToString(), "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture) <= DateTime.ParseExact("2022-04-01", "MM/dd/yyyy", System.Globalization.CultureInfo.InvariantCulture)

DateTime.ParseExact("03/26/2015", "MM/dd/yyyy", CultureInfo.InvariantCulture)

or

DateTime d1  = new DateTime(1990,01,01);

        DateTime d2    = new DateTime(2000, 01, 01);

 

        int result = DateTime.Compare(d1, d2);

 

or

DateTime TodayDate = 

DateTime.ParseExact( DateTime.Now.ToString("dd/MM/yyyy"), 

"dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);

                    if (ExamDate > TodayDate || ExamDate == TodayDate)

                    {

                       

                    } 

or 

DateTime? CreationDate = null;

            DateTime compareDate = DateTime.ParseExact("03/31/2022", "MM/dd/yyyy", System.Globalization.CultureInfo.InvariantCulture);

            if (drp_year.SelectedValue != "0")

            {

                string creationDate = GetCreationDateByEffectiveYear(drp_year.SelectedValue).ToString();

                CreationDate = DateTime.ParseExact(Convert.ToDateTime(creationDate).ToString("MM/dd/yyyy"), "MM/dd/yyyy", System.Globalization.CultureInfo.InvariantCulture);

            }

            if (CreationDate >= compareDate)

            {

                Int64 sixty = Convert.ToInt64(Total * 0.75);

                Int64 forty = Convert.ToInt64(Total * 0.25);

                lbl_sixty.Text = "75% (Demand Based) = " + Convert.ToString(sixty);

                lbl_forty.Text = "25 % = " + Convert.ToString(forty);

            }

or

DateTime dateToCompare = DateTime.ParseExact(DateTime.Now.AddMonths(18).ToString("dd/mm/yyyy"), "dd/mm/yyyy", System.Globalization.CultureInfo.InvariantCulture);

                if (!string.IsNullOrEmpty(DataBinder.Eval(e.Row.DataItem, "DOR").ToString()))

                {

                    if (Convert.ToDateTime(DataBinder.Eval(e.Row.DataItem, "DOR"), System.Globalization.CultureInfo.InvariantCulture) <= dateToCompare)

                    {

                        e.Row.Cells[23].BackColor = System.Drawing.ColorTranslator.FromHtml("#83f383");

                    }

                }

reference:- https://stackoverflow.com/questions/48692170/how-to-add-one-year-to-current-year-using-datetime