Rails 4 - Handling Datetime

Question

I am experiencing strange things when handling Datetime in Rails.

• In my models, I have a datetime column using Postgres.

• My application's Time Zone is set to Central America. However, I am developing in Taiwan's Time Zone (in case it makes a difference.)

• I am using Eonasdan's bootstrap-datetime picker gem fork for selecting dates in my forms.

As per the gem's documentation, I have overwritten Rails' date_select and datetime_select methods like this:

config/initializers/form.rb:

# Add to config/initializers/form.rb or the end of app/helpers/application_helper.rb
module ActionView
  module Helpers
    class FormBuilder 
      def date_select(method, options = {}, html_options = {})
        existing_date = @object.send(method) 
        formatted_date = existing_date.to_date.strftime("%F") if existing_date.present?
        @template.content_tag(:div, :class => "input-group date") do    
          text_field(method, :value => formatted_date, :class => "form-control datepicker", :"data-date-format" => "DD/MM/YYYY") +
          @template.content_tag(:span, @template.content_tag(:span, "", :class => "fa fa-calendar") ,:class => "input-group-addon")
        end
      end

      def datetime_select(method, options = {}, html_options = {})
        existing_time = @object.send(method) 
        formatted_time = existing_time.to_time.strftime("%F %I:%M %p") if existing_time.present?
        @template.content_tag(:div, :class => "input-group date") do    
          text_field(method, :value => formatted_time, :class => "form-control datetimepicker", :"data-date-format" => "DD/MM/YYYY hh:mm A") +
          @template.content_tag(:span, @template.content_tag(:span, "", :class => "fa fa-calendar") ,:class => "input-group-addon")
        end
      end
    end
  end
end

In my view's javascript assets I use the datepicker like this, using the class:

$(function () {
    $('.datetimepicker').datetimepicker({
        format: 'LLL',
        locale: 'es',
        icons: {
                    time: "fa fa-clock-o",
                    date: "fa fa-calendar",
                    up: "fa fa-arrow-up",
                    down: "fa fa-arrow-down",
                    previous: 'fa fa-arrow-left',
                    next: 'fa fa-arrow-right'
                }
        //useCurrent: false,
        //showTodayButton: true
    });
});

As you can see, I am using a special locale and format for displaying the date in the field.

Handling date (using date_select) isn't causing any issue. But handling datetime's time is driving me mad.

For example:

1. I use the datetime_select (with datetime picker) to select a date: 15/02/2016 04:00 PM.

2. I save the record in the database. However, when I check the record using the console, the datetime value stored is 2016-02-15 22:00:00. This is the same date but different time (10pm). What is going on?

3. In my view, I render the date using the following:

   I18n.localize(mydate.to_s.to_datetime, :format => '%d/%m/%Y %I:%M %p')

Which renders the date exactly how it was entered during input: 15/02/2016 04:00 PM. What is Going On?!

Answer 1

ActiveRecord defaults to saving datetime columns in the database as UTC. It will convert the datetime records to/from UTC when you save/load a record. If you want to save the timestamps in the same time zone as your application's time zone, you can add config.active_record.default_timezone = :local to application.rb