CODEWITHSUNDEEP
ruby-on-railstimezoneutc
Blankman
Blankman

Reputation: 266970

How to convert datetime on a per user basis

I have left my application.rb as it was and by default it is storing datetime in UTC.

Now at the UI level (for displaying only) I want to convert the datetime to the user specific timezone.

How can I convert the UTC datetime I get from postgresql and then convert it to the timezone that I will store for each user.

I want to make this conversion using the Offset so like: -5:00 or +4:00

Is it ok to do this, because I was just checking some locations and it seems their offset changes during the season.

E.g. virginia goes from UTC -5 to UTC -4 depending on the month. http://www.timeanddate.com/time/zone/usa/richmond

If UTC is not consistant then I should just store the zone in the database for each user?

Upvotes: 0

Views: 65

Answers (1)

Okomikeruko
Okomikeruko

Reputation: 1173

When I made an app with scheduling events, I had to add timezones to the User model to offset their scheduling.

When I recorded the offset, I used the following code:

<%= time_zone_select "user", 
                     "timezone", 
                     ActiveSupport::TimeZone.us_zones, 
                     {default: "Mountain Time (US & Canada)"},
                     {class: "form-control"} %>

Because Rails has time zones built into their ActiveSupport model. You could use ActiveSupport::TimeZone.all if you wanted users to be global.

Here's some info on time_zone_select

Then depending on how you use it, you can just set

Time.zone = current_user.timezone unless current_user.nil?

or something similar in your application.rb file.

UPDATE

I personally used it to set the timezone in the controller on the only 2 actions where it was necessary.

def index
  @user = current_user
  @pending = @user.share_events.where("time > ?", DateTime.now.in_time_zone(@user.timezone))
  @complete = @user.share_events.where("time <= ?", DateTime.now.in_time_zone(@user.timezone))
end

def new
  @user = current_user
  Time.zone = @user.timezone
  @post = Post.find(params[:post_id])
  @share_event = ShareEvent.new
end

Upvotes: 1

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