How can I get a ruby Time object that represents the start of the day on a particular date in a given timezone.
date = Date.today
date.to_time.in_time_zone('America/New_York').beginning_of_day
Currently outputs => 2011-11-02 00:00:00 -0400
Time.now.in_time_zone('Asia/Shanghai').beginning_of_day
Currently outputs => 2011-11-03 00:00:00 +0800
date = Date.today
date.to_time.in_time_zone('Asia/Shanghai').beginning_of_day
Currently outputs => 2011-11-02 00:00:00 +0800
I ended up using the #local method on the ActiveSupport::TimeZone object passing components of the Date object.
# Get example date and time zone...
date = Date.today
timezone = ActiveSupport::TimeZone['America/New_York']
# Get beginning of day for date in timezone
timezone.local(date.year, date.month, date.day)
David J.
Not sure if this helps, but this gets me the time at which my Google API quotas reset:
# The most recent midnight in California in UTC time
def last_california_midnight
(Time.now.utc - 7.hours).midnight + 7.hours
end
I use it like this with Mongoid, for example:
def api_calls_today
Call.where(updated_at: { '$gte' => last_california_midnight }).count
end
This will work no matter what timezone the code is deployed to, as long Mongo is set to UTC.
来源：https://stackoverflow.com/questions/7988717/get-time-object-at-start-of-day-in-a-particular-time-zone