postgresql_timezones.rb

postgresql_timezones.rb

User.find(885).created_at
"Sun, 31 Aug 2014 22:10:54 BRT -03:00"

User.select('created_at as created_at').where(id: 885)
[#<User id: nil, created_at: "2014-09-01 01:10:54">]

User.select('date(created_at) as created_at').where(id: 885)
[#<User id: nil, created_at: "2014-09-01">]

!!!!!!!!! NÃO! haha. Era pro date ser 2014-08-31. !!!!!!!!!!!

User.select('created_at AT TIME ZONE \'America/Sao_Paulo\' as created_at').where(id: 885)
[#<User id: nil, created_at: "2014-09-01 04:10:54">]

Solução:

User.select("date(created_at AT TIME ZONE \'UTC\' AT TIME ZONE \'#{Time.zone.tzinfo.identifier}\') as created_at").where(id: 885)
[#<User id: nil, created_at: "2014-08-31">]

Time.zone.tzinfo.identifier => 'America/Sao_Paulo'