C# DateTime 日期加1天 减一天 加一月 减一月 等方法88bf必发娱乐

一天前DateTime.Now.AddDays(-1).ToShortDateString().ToString()

//今天   
DateTime.Now.Date.ToShortDateString();   
//昨天,就是今天的日期减一   
DateTime.Now.AddDays(-1).ToShortDateString();   
//明天,同理,加一   
DateTime.Now.AddDays(1).ToShortDateString();   
 
//本周(要知道本周的第一天就得先知道今天是星期几,从而得知本周的第一天就是几天前的那一天,要注意的是这里的每一周是从周日始至周六止   
88bf必发娱乐,DateTime.Now.AddDays(Convert.ToDouble((0 –
Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();   
DateTime.Now.AddDays(Convert.ToDouble((6 –
Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();   
//如果你还不明白,再看一下中文显示星期几的方法就应该懂了   
//由于DayOfWeek返回的是数字的星期几,我们要把它转换成汉字方便我们阅读,有些人可能会用switch来一个一个地对照,其实不用那么麻烦的                 
string[] Day = new string[] { “星期日”, “星期一”, “星期二”,
“星期三”, “星期四”, “星期五”, “星期六” };   
Day[Convert.ToInt16(DateTime.Now.DayOfWeek)];   
 
//上周,同理,一个周是7天,上周就是本周再减去7天,下周也是一样   
DateTime.Now.AddDays(Convert.ToDouble((0 –
Convert.ToInt16(DateTime.Now.DayOfWeek))) – 7).ToShortDateString();   
DateTime.Now.AddDays(Convert.ToDouble((6 –
Convert.ToInt16(DateTime.Now.DayOfWeek))) – 7).ToShortDateString();   
//下周   
DateTime.Now.AddDays(Convert.ToDouble((0 –
Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();   
DateTime.Now.AddDays(Convert.ToDouble((6 –
Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();   
//本月,很多人都会说本月的第一天嘛肯定是1号,最后一天就是下个月一号再减一天。当然这是对的   
//一般的写法   
DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + “1”;
//第一天   
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的字符格式化更简便   
DateTime.Now.ToString(“yyyy-MM-01”);   
DateTime.Parse(DateTime.Now.ToString(“yyyy-MM-01”)).AddMonths(1).AddDays(-1).ToShortDateString();   
 
//上个月,减去一个月份   
DateTime.Parse(DateTime.Now.ToString(“yyyy-MM-01”)).AddMonths(-1).ToShortDateString();   
DateTime.Parse(DateTime.Now.ToString(“yyyy-MM-01”)).AddDays(-1).ToShortDateString();   
//下个月,加去一个月份   
DateTime.Parse(DateTime.Now.ToString(“yyyy-MM-01”)).AddMonths(1).ToShortDateString();   
DateTime.Parse(DateTime.Now.ToString(“yyyy-MM-01”)).AddMonths(2).AddDays(-1).ToShortDateString();   
//7天后   
DateTime.Now.Date.ToShortDateString();   
DateTime.Now.AddDays(7).ToShortDateString();   
//7天前   
DateTime.Now.AddDays(-7).ToShortDateString();   
DateTime.Now.Date.ToShortDateString();   
 
//本年度,用ToString的字符格式化我们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,不用再解释了吧   
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,很多人都会觉得这里难点,需要写个长长的过程来判断。其实不用的,我们都知道一年四个季度,一个季度三个月   
//首先我们先把日期推到本季度第一个月,然后这个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减一   
DateTime.Parse(DateTime.Now.AddMonths(3 – ((DateTime.Now.Month – 1) %
3)).ToString(“yyyy-MM-01”)).AddDays(-1).ToShortDateString();   
//下季度,相信你们都知道了。。。。收工   
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(); 

一天后DateTime.Now.AddDays(1).ToShortDateString().ToString()

addDays(整数)

DateTime.Now.AddDays(10).ToShortDateString().ToString()