کد کلاس:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;


namespace cmsarya.DAL
{

    public class Utility
    {
        public static string lodDate()
        {
            System.Globalization.PersianCalendar pwc = new System.Globalization.PersianCalendar();
            string date = pwc.GetYear(DateTime.Now).ToString() + "/" + pwc.GetMonth(DateTime.Now).ToString("#0#") + "/" + pwc.GetDayOfMonth(DateTime.Now).ToString("#0#");
            return date;
        }
        public static string lodTime()
        {
            DateTime dtt;
            dtt = DateTime.Now;
            string time = dtt.ToString("HH:mm");
            return time;
        } 

    }
}

نحوه فراخوانی در دیگر صفحات CodeBehind  

string Time = cmsarya.DAL.Utility.lodTime();
                string date = cmsarya.DAL.Utility.lodDate();