ruby的日期型

使用 Time 类生成取当前时刻的对象

day = Time.now (或Time.new) p day.to_s   #=> "Sun May 20 23:48:45 JST 2008" p day.year    #=> 2008 p day.month    #=> 5 p day.day    #=> 20 p day.hour    #=> 23 p day.min    #=> 48 p day.sec    #=> 45 p day.wday    #=> 0

使用Time.gm类生成GMT时区时间

day = Time.gm(2008, 5, 20, 23, 59, 59)   #=> Sun May 20 23:59:59 UTC 2008 day = Time.local(2008, 5, 20, 23, 59, 59)   #=> Sun May 20 23:59:59 JST 2008

strftime方法中任意时刻的格式化符号

%A: 星期的名称(如:Sunday, Monday ... )
%a: 星期的名称缩写(如:Sun, Mon ... )
%B: 月份的名称(如:January, February ... )
%b: 月份的名称缩写(如:Jan, Feb ... )
%c: 日期,时刻
%d: 日(01-31)
%H: 24小时制的时间(00-23)
%I: 12小时制的时间(01-12)
%j: 一年中的通算日(001-366)
%M: 分(00-59)
%m: 月(01-12)
%p: 午前和午后(AM,PM)
%S: 秒(00-60)
%w: 一周的天数,周日(0)开始算起(0-6)
%X: 时刻
%x: 日期
%Y: 阳历
%Z: 时区

day = Time.now p day.strftime("Now, %A %B %d %X %Z %Y")   #=> "Now, Sunday May 20 23:33:37 JST 2008"

时刻的加减

day = Time.local(2008, 5, 20, 23, 59, 59)   #=> Sun May 20 23:59:59 JST 2008 day = day + 1   #=>  Mon May 21 00:00:00 JST 2008 day = Time.local(2000, 12, 31, 0, 0, 0)   #=> Sun Dec 31 00:00:00 JST 2000 day = day + 24*60*60   #=>  Mon Jan 01 00:00:00 JST 2008

时刻的求时差

day1 = Time.local(2007, 12, 31, 0, 0, 0)   #=> Sun Dec 31 00:00:00 JST 2007 day2 = Time.local(2008, 1, 2, 12, 30, 0)   #=> Tue Jan 02 12:30:00 JST 2008 days = (day2 - day1).divmod(24*60*60)   #=> [2.0, 45000.0] hours = days[1].divmod(60*60)   #=> [12.0, 1800.0] mins = hours[1].divmod(60)   #=> [30.0, 0.0]

当前日期

require 'date' day = Date::new(2008, 5, 31) p day.to_s    #=> "2008-05-31"

昨天,前天

require 'date' day = Date.new(2008, 5, 31) day = day + 1 p day.to_s    #=> "2008-06-01" day = Date.new(2008, 1, 1) day = day - 1 p day.to_s    #=> "2007-12-31"

下月,上月

require 'date' day = Date.new(2008, 1, 31) day = day >> 1 p day.to_s     #=> "2008-2-28" day = Date.new(2008, 5, 31) day = day << 1 p day.to_s     #=> "2008-04-30"

闰年

require 'date' day = Date.new(2000) p day.leap?    #=> true day = Date.new(2001) p day.leap?    #=> false

日期的格式化

require 'date' day = Date::new(2008, 1, 31) p day.year    #=> 2008 p day.month    #=> 1 p day.day    #=> 31 p day.wday    #=> 3