Question

我的目标是从DateTime实例获取Time实例

此处已在此处讨论，我仍然感到困惑：Convert to/from DateTime and Time in Ruby

对于我来说，运行ruby 1.9.3p0（2011-10-30修订版33570）[x86_64-darwin11.2.0]，事情很顺利

1.9.3p0 :001 > require 'Date'
 => true 
1.9.3p0 :002 > require 'Time'
 => true 
1.9.3p0 :003 > t=DateTime.now
 => #<DateTime: 2012-07-01T01:57:32+05:30 ((2456109j,73652s,621060000n),+19800s,2299161j)> 
1.9.3p0 :004 > t2=t.to_time
 => 2012-07-01 01:57:32 +0530 
1.9.3p0 :005 > t.class
 => DateTime 
1.9.3p0 :006 > t2.class
 => Time 
1.9.3p0 :007 >

但是在同一个ruby平台上使用rails console v 3.2.3时

1.9.3p0 :001 > t=DateTime.now
 => Sun, 01 Jul 2012 02:00:00 +0530 
1.9.3p0 :002 > t.class
 => DateTime 
1.9.3p0 :003 > t2=t.to_time
 => Sun, 01 Jul 2012 02:00:00 +0530
1.9.3p0  > t2.class
 => DateTime

如何从rails中的DateTime获取Time实例？

Answer 1

根据Rails documentation for DateTime.to_time()，

如果self的偏移量不是0，那么self将只返回不变的

要更改为0偏移，请使用DateTime.utc()。

1.9.3p194 :005 > t3=t2.utc
 => Sat, 30 Jun 2012 20:43:21 +0000 
1.9.3p194 :006 > t3.offset
 => (0/1) 
1.9.3p194 :007 > t4=t3.to_time
 => 2012-06-30 20:43:21 UTC 
1.9.3p194 :008 > t4.class
 => Time

DateTime to Time转换中奇怪的Ruby行为

1 个答案: