DateTime dt = DateTime.Now; //當(dāng)前時(shí)間
DateTime startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d"))); //本周周一
DateTime endWeek = startWeek.AddDays(6); //本周周日
DateTime startMonth = dt.AddDays(1 - dt.Day); //本月月初
DateTime endMonth = startMonth.AddMonths(1).AddDays(-1); //本月月末
DateTime startQuarter = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day); //本季度初
DateTime endQuarter = startQuarter.AddMonths(3).AddDays(-1); //本季度末
DateTime startYear = new DateTime(dt.Year, 1, 1); //本年年初
DateTime endYear = new DateTime(dt.Year, 12, 31); //本年年末 //本周(要知道本周的第一天就得先知道今天是星期幾,從而得知本周的第一天就是幾天前的那一天,要注意的是這里的每一周是從周日始至周六止
string thisWeekStart = DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString(); string thisWeekEnd = DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString(); //上周,同理,一個(gè)周是7天,上周就是本周再減去7天,下周也是一樣
string lastWeekStart = DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString(); string lastWeekEnd = DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString(); //下周
string nextWeekStart = DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString(); string nextWeekEnd = DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString(); //本月,本月的第一天嘛肯定是1號(hào),最后一天就是下個(gè)月一號(hào)再減一天。
DateTime thisMonthStart = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1"; //第一天
DateTime thisMonthEnd = DateTime.Parse(DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1").AddMonths(1).AddDays(-1).ToShortDateString();//最后一天 //巧用C#里ToString的字符格式化更簡(jiǎn)便
DateTime.Now.ToString("yyyy-MM-01"); DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).AddDays(-1).ToShortDateString(); //上個(gè)月,減去一個(gè)月份
DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(-1).ToShortDateString(); DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString(); //下個(gè)月,加去一個(gè)月份
DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).ToShortDateString(); DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(2).AddDays(-1).ToShortDateString(); //本年度,用ToString的字符格式化我們也很容易地算出本年度的第一天和最后一天
DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).ToShortDateString(); DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).AddDays(-1).ToShortDateString(); //上年度,不用再解釋了吧
DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(-1).ToShortDateString(); DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddDays(-1).ToShortDateString(); //下年度
DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).ToShortDateString(); DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(2).AddDays(-1).ToShortDateString(); //本季度,很多人都會(huì)覺(jué)得這里難點(diǎn),需要寫個(gè)長(zhǎng)長(zhǎng)的過(guò)程來(lái)判斷。其實(shí)不用的,我們都知道一年四個(gè)季度,一個(gè)季度三個(gè)月 //首先我們先把日期推到本季度第一個(gè)月,然后這個(gè)月的第一天就是本季度的第一天了
DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01"); //同理,本季度的最后一天就是下季度的第一天減一 DateTime.Parse(DateTime.Now.AddMonths(3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString(); //下季度
DateTime.Now.AddMonths(3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01"); DateTime.Parse(DateTime.Now.AddMonths(6 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString(); //上季度
DateTime.Now.AddMonths(-3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01"); DateTime.Parse(DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();