using System; namespace ConsoleApp2 { class Program { static void Main(string[] args) { Console.WriteLine("本季度第一天:{0}", GetQuarterFirstDate(DateTime.Now)); Console.Read(); } /// <summary> /// 获取本季季初, 本季度第一天 /// </summary> /// <param name="dateTime">当前时间 DateTime.Now or DateTime.UtcNow</param> /// <returns>后面的具体时、分、秒和传入值相等</returns> public static DateTime GetQuarterFirstDate(DateTime dateTime) { // 本季季初 return dateTime.AddMonths(0 - ((dateTime.Month - 1) % 3)).AddDays(1 - dateTime.Day); } } }