How to get record created today by rails activerecord?

Post.where(created_at: Time.zone.now.beginning_of_day..Time.zone.now.end_of_day)

PS: This answer has been modified as answer by Harish Shetty was better than mine. As my answer is accepted one. I have updated this answer for community support

I know this question has an accepted answer. The solution suggested in the accepted answer can cause performance issues when the table size grows.

Typically, if you perform lookups based on created_at column, add an index on the table in your migration file.

add_index :posts, :created_at

Now, to lookup records created today:

Rails 3/4

Post.where("created_at >= ?", Time.zone.now.beginning_of_day)

To lookup posts created on a specific day.

Post.where(:created_at => (date.beginning_of_day..date.end_of_day))

--------- OR -------------

Add a static method to your model

class Post < ActiveRecord::Base
  def self.today
    where("created_at >= ?", Time.zone.now.beginning_of_day)
  end
end

Post.today #returns posts today

Rails 2

Post.all(:conditions => ["created_at >= ?", Time.zone.now.beginning_of_day])

--------- OR -------------

Add a named_scope to your model

class Post < ActiveRecord::Base    
  named_scope :today, lambda { 
    {
      :conditions => ["created_at >= ?", Time.zone.now.beginning_of_day]
    }
  }
end

Post.today #returns posts today

MySQL:

Model.all :condition => ["DATE(created_at) = ?", Date.today] # rails 2
Model.where("DATE(created_at) = ?", Date.today) # rails 3

PostgreSQL:

Model.all :condition => ["created_at::date = ?", Date.today] # rails 2
Model.where("created_at::date = ?", Date.today) # rails 3