将Ruby on Rails 5 datetime转换为相对于时区的毫秒

Question

我试图将rails datetime转换为毫秒，但是当我调用.strftime或.to_i它会忽略分配给它的时区并读取系统的时区

system timezone: Europe/London # currently is +01:00 due to BST

# application.rb
config.time_zone = 'Europe/Athens' # +03:00

stored in database as GMT: 2019-04-19 10:00:00.000000

start_date: schedule.start_date,
to_datetime: schedule.start_date.to_datetime,
strftime: schedule.start_date.to_datetime.strftime('%Q').to_i,

start_date: "2019-04-19T13:00:00.000+03:00",
to_datetime: "2019-04-19T13:00:00.000+03:00",
strftime: 1555668000000, # 2019-04-19T11:00:00.000+01:00

它在视图中正确呈现

<%= schedule.start_date %>
# 13:00:00 19 Apr 2019

irb(main):004:0> Time.at(1555668000)
=> 2019-04-19 11:00:00 +0100

如果之前已经回答过，我很抱歉，但我找不到满意的解决方案。

Answer 1

我最终做了这样的事情

system timezone: UTC

# application.rb
config.time_zone = 'UTC'

然后我实现了一个类似于http://railscasts.com/episodes/106-time-zones-revised的时区切换器

dst = Time.zone.now.dst?
offset = Time.zone.utc_offset
offset += 3600 if dst

ts = (schedule.start_date.to_i + offset) * 1000