Ruby / Rails：将Date转换为UNIX时间戳
我如何从Rails应用程序的Date对象获取UNIX时间戳（1970年GMT以来的秒数）？
How would I get a UNIX timestamp (number of seconds since 1970 GMT) from a Date object in a Rails app?
我知道时间＃to_i 返回时间戳，但是执行 Date＃to_time 然后获取时间戳会导致大约一个月的时间（不知道为什么...）
I know Time#to_i returns a timestamp, but doing Date#to_time and then getting the timestamp results in something that's off by about a month (not sure why...).
感谢任何帮助，谢谢！
编辑：好的，我想我想到了 - 我是在循环中处理日期多次，每次由于时区不匹配而移动一点日期，最终导致我的时间戳一个月。不过，我有兴趣知道是否有任何方法可以不依赖 Date＃to_time 。
OK, I think I figured it out- I was processing a date several times in a loop, and each time the date was moved a little because of a time zone mismatch, ultimately leading to my timestamp being a month off. Still, I'd be interested in knowing if there's any way to do this without relying on Date#to_time.
代码 date.to_time.to_i 应该可以正常工作。下面的Rails控制台会话显示了一个例子：
The code date.to_time.to_i should work fine. The Rails console session below shows an example:
>> Date.new(2009,11,26).to_time
=> Thu Nov 26 00:00:00 -0800 2009
>> Date.new(2009,11,26).to_time.to_i
=> 1259222400
>> Time.at(1259222400)
=> Thu Nov 26 00:00:00 -0800 2009
请注意，中间的DateTime对象在本地时间，所以时间戳可能是您期望的几个小时。如果你想在UTC时间工作，你可以使用DateTime的方法to_utc。
Note that the intermediate DateTime object is in local time, so the timestamp might be a several hours off from what you expect. If you want to work in UTC time, you can use the DateTime's method "to_utc".