Honor timezones from timeanddate.com

[nobu]

Fix #25

[ritikesh]

Hey @nobu / @jeremyevans, thanks for fixing this. Quick question, will this be back ported to currently supported versions of Ruby? What versions will it be available in?

[jeremyevans]

I assume it will be available in Ruby 3. Note that in all supported versions of Ruby, date is a default gem, so after the next release of the date gem, you should be able to gem install date, then in your code use gem 'date' before require 'date', to use the gem version instead of the stdlib version.

[ritikesh]

We run a rails app in production, and tried adding date gem before rails. Still the same incorrect timezone for CAT.

# Gemfile
source 'https://rubygems.org'

ruby '2.7.1'

gem 'date', git: 'https://github.com/ruby/date', branch: 'master'

gem 'rails', '~> 6.0.0'
....

2.7.1 :002 > DateTime.parse("2020-10-01 00:00:00 CAT")
 => Thu, 01 Oct 2020 00:00:00 -1000

[jeremyevans]

That's a bundler issue I would guess (maybe bundler or the webserver loads date). I think to be sure the updated date library is used, checkout the date master branch, and use RUBYLIB=/path/to/date/lib in the environment when running your application.

[ritikesh]

Tried with RUBYLIB, but it didn't help either:

# Gemfile
source 'https://rubygems.org'

ruby '2.7.1'

gem 'date', git: 'https://github.com/ruby/date', branch: 'master'

gem 'rails', '~> 6.0.0'
....

RUBYLIB='/Users/user/.rvm/gems/ruby-2.7.1@gemset/bundler/gems/date-f08175e34d60' bundle exec rails c
Running via Spring preloader in process 72907
Loading development environment (Rails 6.0.3.2)

2.7.1 :001 > DateTime.parse('2020-10-01 00:00:00 CAT')
 => Thu, 01 Oct 2020 00:00:00 -1000

Let me dig deeper, thank you for your time!

[jeremyevans]

RUBYLIB in your example looks wrong. Do an actual checkout of the date repository, run rake compile in it, and set RUBYLIB=/path/to/date/lib (note the /lib at the end). Then try RUBYLIB=/path/to/date/lib ruby -r date -e "DateTime.parse('2020-10-01 00:00:00 CAT')" to see if it works.

[geophilusd]

I tried this out in ruby version 3.0.2
Looks like these changes are not reflected.

require 'date'
3.0.2 :002 > DateTime.parse("2021-08-09 19:39:31 CAT")
 => #<DateTime: 2021-08-09T19:39:31-10:00 ((2459437j,20371s,0n),-36000s,2299161j)> 
3.0.2 :003 > DateTime.parse("2021-08-09 19:39:31 SST")
 => #<DateTime: 2021-08-09T19:39:31+02:00 ((2459436j,63571s,0n),+7200s,2299161j)> 

[jeremyevans]

It turns out these changes aren't even in the date master branch. It looks like we missed the regeneration of zonetab.h. I'll send a pull request for that.

[geophilusd]

Can we expect this to be fixed in the next ruby release?

[geophilusd]

@jeremyevans In which ruby version will this be fixed?

[jeremyevans]

Ruby master branch has the fixed zonetab.h, so Ruby 3.1 will contain the fix.