I'm in Korea.
Rails version is 2.3.5
in my environment,
config.time_zone = 'Seoul'
config.active_record.default_timezone = 'Seoul'
created_at and updated_at value is inserted with local time in database.
but, when I access model.created_at or model.updated_at,
the value is understanding with UTC +9:00
So, I insert model to database and get the value, and check difference both values immediately,
It is different bellow:
>> Time.now.to_datetime
=> Sun, 24 Jan 2010 21:28:03 +0900
# insert new Product. And check difference Time.now and Product.created_at immediately.
>> Product.last.created_at.to_datetime
=> Mon, 25 Jan 2010 06:12:51 +0900
Is it a bug of rails?
There is a known bug in Rails:
Rails Timezone Gotcha: ActiveRecord::Base.find does not convert Time objects to UTC
http://marklunds.com/articles/one/402
Related
I am trying to set the ActiveRecord's time zone from UTC to current time zone. This is what I ended up
Application.rb
module application
class Application < Rails::Application
config.load_defaults 5.2
config.time_zone = 'Tokyo'.freeze
config.active_record.default_timezone = :local
end
end
I have turned off the server and restarted and made an object then when I checked the object's created_at it seems the ActiveRecords still records the data based on UTC time not Tokyo time.
Any solutions guys?
It always records the data of DateTime as UTC in Database and it will be converted according to config.time_zone if you call object.created_at
Let's say, It stored 2018-09-17 04:41:00 or Fri, 17 Sep 2018 04:41:00 UTC +00:00 in the database.
If your config the timezone as Tokyo then the result is Fri, 17 Sep 2018 13:41:00 JST +09:00
Additionally, you can use .in_time_zone method to convert the DateTime based on that zone. Here's .in_time_zone
I have the timezone set.
config.time_zone = 'Mountain Time (US & Canada)'
Creating a Christmas event from the console...
c = Event.new(:title => "Christmas")
using Time:
c.start = Time.new(2012,12,25)
=> 2012-12-25 00:00:00 -0700 #has correct offset
c.end = Time.new(2012,12,25).end_of_day
=> 2012-12-25 23:59:59 -0700 #same deal
using DateTime:
c.start = DateTime.new(2012,12,25)
=> Tue, 25 Dec 2012 00:00:00 +0000 # no offset
c.end = DateTime.new(2012,12,25).end_of_day
=> Tue, 25 Dec 2012 23:59:59 +0000 # same
I've carelessly been using DateTime thinking that input was assumed to be in the config.time_zone but there's no conversion when this gets saved to the db. It's stored just the same as the return values (formatted for the db).
Using Time is really no big deal but do I need to manually offset anytime I'm using DateTime and want it to be in the correct zone?
Yep. Time.new will intepret parameters as local time in the absence of a specific timezone, and DateTime.new will intepret parameters as UTC in the absence of a specific timezone. As documented. You may want to replace Time.new with Time.local for clarity throughout your code.
What you can do is use DateTime's mixins for Time to invoke Time.local(2012,12,25).to_datetime. But if the year/month/day is coming from a user/browser, then perhaps you should get the user's/browser's timezone instead of using your server's.
If you need to create a migration to fix existing data in the DB, new_date_time = Time.local(old_date_time.year, old_date_time.mon, old_date_time.mday, old_date_time.hour, old_date_time.min, old_date_time.sec).to_datetime
i've got a Course model, which has a datetime attribute. If I look at it from the database i get one time, and if i look at it from the object i get a different date & time.
>> Course.last.attribute_for_inspect :datetime
=> "\"2012-01-04 01:00:00\""
>> Course.last.datetime
=> Tue, 03 Jan 2012 19:00:00 CST -06:00
Does anyone know why this value is different, and what I can do to fix it? The time from Course.last.datetime is correct, but my queries on the course table aren't working correctly due to the mix-up.
From the fine manual:
attribute_for_inspect(attr_name)
Returns an #inspect-like string for the value of the attribute attr_name.
[...]
Date and Time attributes are returned in the :db format.
So, when attribute_for_inspect is used for a datetime, it will return the string that the database uses for that value. Rails stores times in the database in UTC and any sensible database will use ISO 8601 for formatting timestamps on the way in and out.
2012-01-04 01:00:00 is the UTC timestamp in ISO 8601 format. When Rails returns a datetime, it converts it to an ActiveSupport::TimeWithZone instance and includes a timezone adjustment based on the timezone that you have configured in your application.rb. You're using the CST timezone and that's six hours behind UTC; subtracting six hours from 01:00 gives you 19:00 and you lose a day from crossing midnight. The human friendly format, Tue, 03 Jan 2012 19:00:00 CST -06:00, is just how ActiveSupport::TimeWithZone represents itself when inspected and the console uses x.inspect to display x.
As far as fixing your queries goes, just use t.utc before sending in a time t and you should be good.
Configuring your Rails App Timezone in application.rb
set config.active_record.default_timezone to :local as it is set to :utc by default in the application.rb
paste this code in your application.rb
config.active_record.default_timezone = :local #or :utc
config.time_zone = "Singapore" #your timezone
I added this line of code
self.auth_history.push [start_date, self.coupon_code]
And got this error message
Date is not currently supported; use a UTC Time instance instead.
I also tried start_date.utc, but it didn't work either.
Please help. Thanks.
I got this answer from Seattle Brigade group -
===
I didn't see start_date defined in your code as a key in MongoMapper, so
I'll assume you're creating your own date object, either directly via Ruby,
or wrapped by Rails. As far as I know, and someone please correct me, Mongo
stores dates as UTC time in milliseconds since epoch. So when you define a
key with a :date mapping in MongoMapper, you're wrapping a Time object in
Ruby.
Therefore, if you want to store a date inside of Mongo, and it wasn't
created by MongoMapper, make sure you create a Time object in UTC.
MongoMapper comes with a Date mixin method called to_mongo that you can use.
>> Time.now.utc
=> Fri Jan 28 03:47:50 UTC 2011
>> require 'date'
=> true
>> date = Date.today
=> #<Date: 4911179/2,0,2299161>
>> Time.utc(date.year, date.month, date.day)
=> Thu Jan 27 00:00:00 UTC 2011
>> require 'rubygems'
=> true
>> require 'mongo_mapper'
=> true
>> Date.to_mongo(date)
=> Thu Jan 27 00:00:00 UTC 2011
But watch out for the time change.
>> Date.to_mongo(Time.now)
=> Thu Jan 27 00:00:00 UTC 2011
>> Date.to_mongo(Time.now.utc)
=> Fri Jan 28 00:00:00 UTC 2011
Good luck.
===
And by using
Date.to_mongo(start_date)
it works for me.
First, I think the question title is bad in description. Actually, the difference between different timezone is on Time not on Date. So, it's really not proper to say I want to convert a date to UTC format.
Here is another way in Ruby to convert DateTime to its UTC format:
DateTime.now.new_offset(0)
Here's another option:
Time.at(Date.today.to_datetime.to_i).utc
Here I am using Date.today as an arbitrary example date. Replace with whatever date you want to convert. Once the date is converted to a Time instance, it can be serialized to BSON without any problem, as Time is a supported primitive type, that is to say, it can be saved using MongoMapper to the database.
As per EfratBlaier's comment I have updated the answer.
Date.today.to_time.utc
I have a rails time-based query which has some odd timezone sensitive behaviour, even though as far as I know I'm using UTC. In a nutshell, these queries give different answers:
>> Model.find(:all,:conditions=>['created_at<=?',(Time.now-1.hours).gmtime]).length
=> 279
>> Model.find(:all,:conditions=>['created_at<=?',(Time.now-1.hours)]).length
=> 280
Where the DB actually does contain one model created in the last hour, and the total number of models is 280. So only the first query is correct.
However, in environment.rb I have:
config.time_zone = 'UTC'
The system time zone (as reported by 'date') is BST (which is GMT+1) - so somehow this winds up getting treated as UTC and breaking queries.
This is causing me all sorts of problems as I need to parameterise the query passing in different times to an action (which are then converted using Time.parse()), and even though I send in UTC times, this 'off by one hour' DST issue crops a lot. Even using '.gmtime()' doesn't always seem to fix it.
Obviously the difference is caused somehow by an implicit conversion somewhere resulting in BST being incorrectly treated as UTC, but why? Doesn't rails store the timestamps in UTC? Isn't the Time class timezone aware? I am using Rails 2.2.2
So what is going on here - and what is the safe way to program around it?
edit, some additional info to show what the DB and Time class are doing:
>> Model.find(:last).created_at
=> Tue, 11 Aug 2009 20:31:07 UTC +00:00
>> Time.now
=> Tue Aug 11 22:00:18 +0100 2009
>> Time.now.gmtime
=> Tue Aug 11 21:00:22 UTC 2009
The Time class isn't directly aware of your configured timezone. Rails 2.1 added a bunch of timezone support, but Time will still act upon your local timezone. This is why Time.now returns a BST time.
What you likely want is to interact with Time.zone. You can call methods on this like you would the Time class itself but it will return it in the specified time zone.
Time.zone.now # => Tue, 11 Aug 2009 21:31:45 UTC +00:00
Time.zone.parse("2:30 PM Aug 23, 2009") # => Sun, 23 Aug 2009 14:30:00 UTC +00:00
Another thing you have to be careful with is if you ever do queries on the database where you are comparing times, but sure to use the UTC time (even if you have a different time zone specified) because Rails always stores UTC in the database.
Item.all(:conditions => ["published_at <= ?", Time.now.utc])
Also, instead of Time.now-1.hour do 1.hour.ago. It is easier to read and Rails will automatically use the configured timezone.
The TimeZone you need to set is UK, this will automatically handle BST
Time.zone = 'UK'
Time.zone.now
=> Sun, 17 Oct 2010 02:09:54 BST +01:00
start_date_format = DateTime.strptime(#start_date, date_format)
start_date_format_with_hour =
DateTime.strptime((start_date_format.to_i + timezone_offset*60*60).to_s,'%s').strftime(date_format)
end_date_format = DateTime.strptime(#end_date, date_format)
end_date_format_with_hour = DateTime.strptime((end_date_format.to_i + timezone_offset*60*60).to_s,'%s').strftime(date_format)
#filters_date = "invoices.created_at >= ? AND invoices.created_at < ?", start_date_format_with_hour, end_date_format_with_hour