我怎么能得到昨天的约会？

Question

我怎么能得到昨天的约会？

也许:

@get_time_now    = Time.now.strftime('%m/%d/%Y') / 86400 

要么

@get_time_now    = Time.now.strftime('%m/%d/%Y') - 1.day

要么

@get_time_now    = Time.now. / 86400 

86400 = 1天,对吗？(60*60*24)

Answer 1

对于日期对象,您可以使用:

Date.yesterday

或者是时间对象:

1.day.ago

或者在铁轨之外:

Date.today.prev_day

Answer 2

尝试1.day.ago和变种后:

irb(main):005:0> 1.day.ago
NoMethodError: undefined method `day' for 1:Fixnum

如果发现Date.today.prev_day对我有用:

irb(main):016:0> Date.today.prev_day
=> #<Date: 2013-04-09 ((2456392j,0s,0n),+0s,2299161j)>

Answer 3

Time.now - (3600 * 24)   # or Time.now - 86400

要么

require 'date'

Date.today.prev_day

Answer 4

使用 Date.today - 1.days。

Date.yesterday 取决于当前时间以及与 GMT 的偏移量

1.9.3-p125 :100 > Date.today
 => Wed, 29 Feb 2012 
1.9.3-p125 :101 > Date.yesterday
 => Wed, 29 Feb 2012 
1.9.3-p125 :102 > Date.today - 1.days
 => Tue, 28 Feb 2012 

Answer 5

Ruby 2.1.2原生时间

回答:

Time.at(Time.now.to_i - 86400)

证明:

2.1.2 :016 > Time.now
 => 2014-07-01 13:36:24 -0400 
2.1.2 :017 > Time.now.to_i
 => 1404236192 
2.1.2 :018 > Time.now.to_i - 86400
 => 1404149804 
2.1.2 :019 > Time.at(Time.now.to_i - 86400)
 => 2014-06-30 13:36:53 -0400 

一天的秒数.

86400 = 1天(60*60*24)

Answer 6

使用 DateTime.now - 1

1.9.3p194 :040 > DateTime.now
 => Mon, 18 Nov 2013 17:58:45 +0530 
1.9.3p194 :041 > DateTime.now - 1
 => Sun, 17 Nov 2013 17:58:49 +0530 

或 DateTime.yesterday

1.9.3p194 :042 > DateTime.yesterday
 => Sun, 17 Nov 2013 

或者我们可以使用rails advance方法Time和DateTime

1.9.3p194 :043 > Time.now.advance(days: -1)
 => 2013-11-17 17:59:36 +0530
1.9.3p194 :044 > DateTime.now.advance(days: -1)
 => Sun, 17 Nov 2013 17:59:49 +0530

advance 方法也提供了这个选项 :years, :months, :weeks, :days, :hours, :minutes, :seconds

日期时间提前方法

时间提前法