C# 时间处理

using System;
using System.Globalization;

namespace Common
{
    /// <summary>
    /// 时间处理
    /// </summary>
    public class DateTimeCommonHandler
    {
        /// <summary>
        /// 获取时间是一年的第几周
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public int GetWeekNum(DateTime dt)
        {
            GregorianCalendar gc = new GregorianCalendar();
            int weekOfYear = gc.GetWeekOfYear(dt, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
            return weekOfYear;
        }

        /// <summary>
        /// C#获取指定日期时间是当前年度的第几个季度
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public int GetQuarterNum(DateTime dt)
        {
            var mouth = dt.Month;
            int quarter = mouth % 3 == 0 ? mouth / 3 : (mouth / 3 + 1);
            return quarter;
        }

        /// <summary>
        /// 求时间段间隔天数
        /// </summary>
        /// <param name="dateStart"></param>
        /// <param name="dateEnd"></param>
        /// <returns></returns>
        public int DateDiff(DateTime dateStart, DateTime dateEnd)
        {
            DateTime start = Convert.ToDateTime(dateStart.ToShortDateString());
            DateTime end = Convert.ToDateTime(dateEnd.ToShortDateString());
            TimeSpan sp = end.Subtract(start);
            return sp.Days + 1;
        }
    }
}