I am using Rails 3.1. Here is my configuration
config.time_zone = "Eastern Time (US & Canada)"
Now user enters Nov 30, 2011 at 7:00 PM. How do I parse this text so that after parsing I get the result in EST?
You can do so by calling time = ActiveSupport::TimeZone.new('EST').parse('Nov 30, 2011 at 7:00 PM'). Also you can parse the time string as being in user-specific or default timezone by calling Time.zone.parse. You can convert the result time into any timezone thanm i.e. Time.zone.now.in_time_zone('Asia/Yekaterinburg')
Also there is no need in do any manual conversions of timezones before storing the time to database as Rails does is automatically.
You should store all values in UTC and render them in user's local time. "Eastern Time" is a loose concept at best and changes on a fairly regular basis as politicians decide to extend or contract Daylight Saving Time.
Generally you can do this with the ActiveSupport::TimeZone methods local_to_utc and utc_to_local conversion methods.
Related
I want to convert the created_at to this format January 12, 2:00 PM PST.
The first step I tried was to convert the created_at field to Pacific Standard Time (PST).
However, I'm stuck - I can't even get past this step.
I've tried these, but neither worked:
Time.parse(self.created_at).in_time_zone('Pacific Time (US & Canada)')
time = Time.parse(self.created_at)
time.in_time_zone('Pacific Time (US & Canada)')
I receive no implicit conversion of ActiveSupport::TimeWithZone into String when I do this.
I based it on these questions:
How do you convert the following time from UTC to EST in Ruby (without Rails)?
How to convert time from UTC to PST in rails
Since it is already a datetime, you should be able to just do this to convert it:
self.created_at.in_time_zone('Pacific Time (US & Canada)')
Don't forget to save the new time zone to the record in the database.
Time.parse() is meant to convert strings into datetime(https://apidock.com/ruby/v2_5_5/Time/parse/class).
I'm having a frustrating issue that I can't seem to narrow down. I have searched many similar articles but they are not close enough to my issue to resolve. I am trying to pull a time from the database and display it in more than one time zone. My Rails app is using UTC as default. Here is what I'm doing:
On the create action I take the string of time which will be saved in the time column in my DB:
params[:schedule][:start] = "09:00"
Time.zone = "Central Time (US & Canada)"
#schedule.start = Time.zone.parse(params[:schedule][:start])
The above formats the time as it is supposed to:
2016-04-12 09:00:00 -0500
This is saved in the DB as:
2000-01-01 14:00:00
This has no time offset which is fine since I know it's in UTC. The problem happens when I go to display the time:
#schedule.start.in_time_zone("Central Time (US & Canada)")
This returns:
Sat, 01 Jan 2000 08:00:00 CST -06:00
Now, since this is a time column, I don't care about the date. I plan on formatting the value to only show the time. However, it is showing CST when it is currently CDT.
I can't figure out why this is happening. As I said I am not setting the Time Zone anywhere in my application.rb or anywhere else and I only set the Time zone on the create action which should be fine when moving to a new action.
Any help on clarifying this would be awesome!
This seems to be because when the time is stored it is stored with the date in the year 2000-01-01 which seems to be why it is using CST. How can I ignore the date when converting it to a particular timezone or will I need to change the column type to DateTime to get this to work properly?
It is showing CST simply because the time is read from the database including the stored date, i.e. it's read as 09:00 of Jan 1st 2000.
I guess you'd have to parse the time upon reading the attribute back. You can use a helper method in your model, for example:
# schedule model
def start_in_zone(zone)
self.start.strftime("%H:%M").in_time_zone(zone)
end
This will take only the hours and minutes part of the stored time and parse it in the given time zone with the date set to today. See this example:
"Sat, 01 Jan 2000 08:00:00".to_time.
strftime("%H:%M").
in_time_zone("Central Time (US & Canada)")
# => Tue, 12 Apr 2016 08:00:00 CDT -05:00
The fact that it matters whether it's CST or CDT means you do, on some level, care about the date. While I'm not familiar with the exact rules of Daylight Savings in that region, I do know that Jan 1 is the middle of winter and will definitely not be on Daylight Savings time.
Add the relevant date into your #schedule before putting it into a time zone, and it should fix the problem.
I have records with a created column whose datetime is stored in UTC.
For instance, this is the datetime stored in one record: 2014-02-01 00:33:25
But if I retrieve that record and confer it to CST, it'd look like this:
Article.find(1).created.in_time_zone('Central Time (US & Canada)') => Fri, 31 Jan 2014 18:33:25 CST -06:00
Which is a different day/month as far as that timezone goes.
The problem I'm having is finding records based on a date. So say I wanted to pull all records for January 31, 2014 (CST). I want to include my example record.
How do I do that in a Rails app? I'm running Rails 4.0.1 and Ruby 2.0.0 with Postgres 9.3.1.0.
Use AT TIME ZONE to change timezone
Article.where("date(created AT TIME ZONE 'UTC' AT TIME ZONE 'CST') = '01/31/2014'")
Got some help outside of SO and got what I was looking for.
Say I wanted to find all records in a date range, this is what it'd be:
Article.where(created: Date.parse("January 1, 2014").in_time_zone('Central Time (US & Canada)').beginning_of_day.utc..Date.parse("January 31, 2014").in_time_zone('Central Time (US & Canada)').end_of_day.utc)
I am working on a rail4 app. Where I want to store dates in all mysql tables in UTC. However I store user's timezone in a specific table, called users. When user logs in, I get user's timezone form user table and save in session.
I am able to save date in all tables in UTC as default value of config.time_zone is UTC for activerecords and activemodels. But while displaying I want to show dates in user's timezone. As well as, when any user inputs a date/time in any html form, then I want to save it in the equivalent UTC format.
What is the best way to achieve this?
Rails, activerecord and MySQL will save all the timestamp fields in UTC. Without you having to do anything.
In your application.rb file where the configuration of the Application is done, you define the default time zone if you want the display of timestamps to take place on time zone different from UTC.
Hence
config.time_zone = 'Central Time (US & Canada)'
will display the timestamp fields (without you having to do anything special in other piece of code) using the Central Time.
When you want each of your users to have timestamps displayed in different time zone you can store the time zone in a column along side the user data. The column can be called time_zone and can contain the string of the user preferred time zone.
But, you have to tell the timestamp object to display itself to the specific timezone. This is done with the help of the method in_time_zone(timezone) that DateTime object responds to.
Example (when the default time zone is UTC):
1.9.3-p194 :004 > d = DateTime.new(2012, 9, 1, 6, 30, 0)
=> Sat, 01 Sep 2012 06:30:00 +0000
1.9.3-p194 :005 > d.in_time_zone("Central Time (US & Canada)")
=> Sat, 01 Sep 2012 01:30:00 CDT -05:00
Or you can change the time zone globally for the request at hand on a before or around filter. There is a documentation on internet if you do a google on that.
Read also this one: http://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html
for various alternatives to approach the problem.
You could store the time in UTC, and store the timezone separately. Timezones are commonly stored as a UTC-offset in seconds (seconds are the SI unit of time).
Then you can display it like so:
utime = Time.now.utc.to_i # this value can be any format that Time.at can understand. In this example I'll use a unix timestamp in UTC. Chances are any time format you store in your DB will work.
=> 1375944780
time = Time.at(utime) # parses the time value (by default, the local timezone is set, e.g. UTC+08:00)
=> 2013-08-08 14:53:00 +0800
time_in_brisbane = time.in_time_zone(ActiveSupport::TimeZone[36000]) # sets the timezone, in this case to UTC+10:00 (see http://stackoverflow.com/a/942865/72176)
=> Thu, 08 Aug 2013 16:53:00 EST +10:00
time_brisbane.strftime("%d %b %Y, %l:%M %p %z") # format with strftime however you like!
=> "08 Aug 2013, 4:53 PM +1000"
I'm using Rails 3.2 and ruby 1.9.3 on Debian. I have an app that collects a date, time, and timezone in the form of strings via an HTML form. Something like this:
start_date: "04-15-2010",
start_time: "10:00:00",
timezone: "Central Time (US & Canada)"
What I'd like to do is parse these 3 elements into a single date that is saved into my database as UTC, which in this case would add 7 hours to the start time, once it's in the UTC time zone.
So the stored time would be 17:00 once it's in the DB as UTC instead of the received Central time.
I have tried something like this to parse the date:
ActiveSupport::TimeZone[timezone].at DateTime.strptime("{ 2012-04-09 20:00:00 }", "{ %Y-%m-%d %H:%M:%S }").to_i
However, I'm not able to incorporate the time zone into the resulting time with %Z. It either doesn't parse or the time is interpreted as UTC not Central time. So my question is, how to coerce a date string into a certain time zone without changing the value of the actual date/time stored. I'd like to be able to parse the string into a date/time object that includes the correct time zone with it at that time so that future time zone conversions are accurate. I've looked all over and can't find a way to do this. It's strange, since this seems like something common one does with dates inputted from HTML forms. Thank you for any help.
Try this:
zone = "Central Time (US & Canada)"
ActiveSupport::TimeZone[zone].parse("2013-04-03 17:47:00")
Use String#in_time_zone (Rails 4+)
I personally prefer using String#in_time_zone:
>> '22.09.1986 10:30'.in_time_zone('Central Time (US & Canada)')
# => Mon, 22 Sep 1986 10:30:00 CDT -05:00
This parses the date and time in the String into the time zone provided.
%Z is the correct way to specify a Time zone name. Have you tried the following ?
date_and_time = '%m-%d-%Y %H:%M:%S %Z'
DateTime.strptime("04-15-2010 10:00:00 Central Time (US & Canada)",date_and_time)
This is the method that I came up with. Not the prettiest, but it works. Allows parsing the string using a specified format, and then turning it into the format that I know Time.zone.parse requires.
class ActiveSupport::TimeZone
def strptime(time, format='%m/%d/%Y')
formatted = Time.strptime(time, format).strftime('%Y-%m-%d %T')
parse(formatted)
end
end
Then you can do something like what was mentioned in another question, but with a specified format:
zone = "Central Time (US & Canada)"
ActiveSupport::TimeZone[zone].strptime('2013-04-03', '%Y-%m-%d')
Or if you already have a time zone set:
Time.zone = "Central Time (US & Canada)"
Time.zone.strptime('01/13/2006')
I used a default format of %m/%d/%Y because that's what my user input is most of the time. You can customize this to your needs, or use the default format DateTime uses which is believe is iso8601 (%FT%T%z)
I've finally found the dirty, yet definitive way to do this.
First, parse the string using plain Ruby Time.strptime like this:
time = Time.strptime('12 : 00 : PM', '%I : %M : %p')
This way you get the parsed Time, but not yet in correct timezone. To fix that, let's convert the time to string form and parse it with the standard ActiveSupport::TimeZone#parse
Time.zone.parse(time.to_s)
The result is the ActiveSupport::TimeWithZone with our time parsed into the correct timezone.
The reason why we have to do it this way is that neither ActiveSupport::TimeZone nor ActiveSupport::TimeWithZone support the strptime method. So we have to parse the Time with core Ruby strptime that does not have timezone information, convert it to format acceptable in ActiveSupport objects and then parse it yet again.
To have DateTime take the date string and attach a timezone other than UTC without changing the values of the date string , use this, its easy , doesnt break on leap day :)
xx = DateTime.strptime("9/1/15 #{object.time_zone}", "%m/%d/%Y %Z")
Convert specific date format in UTC.
ActiveSupport::TimeZone['UTC'].parse(Time.strptime('01/24/2019T16:10:16', "%m/%d/%YT%H:%M:%S").asctime)