Rails在datetime上出现时区问题

Question

I have a rails app with events. My event table has a field called start_date which is of datetime type. Currently when i save an event using chronic to parse the start_date field, the date gets incorrectly stored (or at least returns incorrectly).

Example: I saved an event and in the textfield for start_date i entered 9/14/13 at 9am . It saved the data, refreshed the page, and the value in the textfield was 9/14/13 at 11am . The value in the mysql table is 2013-09-14 16:00:00 .

What is going on here? This only happens on my server and not when running locally.

application.rb:

config.time_zone = 'Central Time (US & Canada)'

models/event.rb:

class Event < ActiveRecord::Base
    belongs_to :user
    attr_accessible :description, :name, :start_date_string

    validate :name_not_blank
    validate :start_date_not_blank

    # Validate that the name is not blank
    def name_not_blank
        errors.add(:name, "Name can't be blank") unless !name.blank?
    end

    # Validate that the name is not blank
    def start_date_not_blank
        errors.add(:start_date, "Date and Time can't be blank") unless !start_date.blank?
    end

    # getter
    def start_date_string
        @start_date_string || start_date.in_time_zone.try(:strftime, "%m/%d/%Y at %I:%M %P")
    end

    # setter
    def start_date_string=(value)
        @start_date_string = value
        self.start_date = parse_start_date
    end

    # parse the start_date
    def parse_start_date
        Chronic.parse(start_date_string)
    end     
end

helpers/application_helper.rb:

# Formats a date to words (i.e. March 20, 1980 at 10:00 am)
def spell_date_and_time(date) 
    date.strftime("%B %d, %Y at %I:%M %P")
end

edit.html.erb

<span class="timestamp"><%= spell_date_and_time(event.start_date) %></span>

Answer 1

Assuming 'Central Time (US & Canada)' is correct (ie you are not on the Eastern time zone), then:

• You don't need in_time_zone , rails will do this for you with the current Time.zone
• You need to set Chronic to use your timezone with Chronic.time_class (by default, the built in Ruby time class creates times in your system's local time zone.)

 > Time.zone = "UTC" > Chronic.time_class = Time.zone > Chronic.parse("June 15 2006 at 5:45 AM") => Thu, 15 Jun 2006 05:45:00 UTC +00:00 

You can put Chronic.time_class = Time.zone it in config/initializers/chronic.rb

Answer 2

Sorry, I'm on the tablet so this will have to be brief. I've had a problem like this and corrected it by using something like

Time.now.utc 

I do see that you have in the application.rb config.time_zone though, so this may not work.

If it doesn't, here's a good SO answer, maybe it will help

Why doesn't `config.time_zone` seem to do anything?

Answer 3

I had same issue, solved it by adding this in application.rb-

config.time_zone = 'Central Time (US & Canada)'
config.active_record.default_timezone = :local

Answer 4

I had same issue and I just fixed it by commenting this line in my application.rb:

config.active_record.default_timezone = :local

I did this according to what I read in the application.rb:

# Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
# Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.