diff --git a/bin/crono b/bin/crono
index f2fb30d..27653d4 100755
--- a/bin/crono
+++ b/bin/crono
@@ -1,8 +1,8 @@
 #!/usr/bin/env ruby
 
-$LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
+$LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)
 
-require "crono/cli"
+require 'crono/cli'
 
 begin
   Crono::CLI.instance.run
diff --git a/examples/cronotab.rb b/examples/cronotab.rb
index 647d841..bb8c429 100644
--- a/examples/cronotab.rb
+++ b/examples/cronotab.rb
@@ -1,4 +1,4 @@
-# cronotab.rb — Crono configuration file
+# cronotab.rb - Crono configuration file
 #
 # Here you can specify periodic jobs and schedule.
 # You can use ActiveJob's jobs from `app/jobs/`
@@ -7,9 +7,8 @@
 #
 class TestJob
   def perform
-    puts "Test!"
+    puts 'Test!'
   end
 end
 
-Crono.perform(TestJob).every 2.days, at: "15:30"
-
+Crono.perform(TestJob).every 2.days, at: '15:30'
diff --git a/lib/crono.rb b/lib/crono.rb
index b7ebce9..a03f4a4 100644
--- a/lib/crono.rb
+++ b/lib/crono.rb
@@ -1,14 +1,15 @@
+# Crono main module
 module Crono
 end
 
-require "active_support/all"
-require "crono/version"
-require "crono/logging"
-require "crono/period"
-require "crono/job"
-require "crono/scheduler"
-require "crono/config"
-require "crono/performer_proxy"
-require "crono/orm/active_record/crono_job"
+require 'active_support/all'
+require 'crono/version'
+require 'crono/logging'
+require 'crono/period'
+require 'crono/job'
+require 'crono/scheduler'
+require 'crono/config'
+require 'crono/performer_proxy'
+require 'crono/orm/active_record/crono_job'
 
-Crono.autoload :Web, "crono/web"
+Crono.autoload :Web, 'crono/web'
diff --git a/lib/crono/cli.rb b/lib/crono/cli.rb
index 362cfd7..00db2e7 100644
--- a/lib/crono/cli.rb
+++ b/lib/crono/cli.rb
@@ -4,6 +4,7 @@ require 'optparse'
 module Crono
   mattr_accessor :scheduler
 
+  # Crono::CLI - Main class for the crono daemon exacutable `bin/crono`
   class CLI
     include Singleton
     include Logging
@@ -18,12 +19,7 @@ module Crono
     def run
       parse_options(ARGV)
 
-      if config.daemonize
-        set_log_to(config.logfile)
-        daemonize 
-      else
-        set_log_to(STDOUT)
-      end
+      setup_log
 
       write_pid
       load_rails
@@ -33,7 +29,17 @@ module Crono
       start_working_loop
     end
 
-  private
+    private
+
+    def setup_log
+      if config.daemonize
+        self.logifile = config.logfile
+        daemonize
+      else
+        self.logfile = STDOUT
+      end
+    end
+
     def daemonize
       ::Process.daemon(true, true)
 
@@ -42,7 +48,7 @@ module Crono
         io.sync = true
       end
 
-      $stdin.reopen("/dev/null")
+      $stdin.reopen('/dev/null')
     end
 
     def write_pid
@@ -54,16 +60,16 @@ module Crono
       logger.info "Loading Crono #{Crono::VERSION}"
       logger.info "Running in #{RUBY_DESCRIPTION}"
 
-      logger.info "Jobs:"
+      logger.info 'Jobs:'
       Crono.scheduler.jobs.each do |job|
-        logger.info %{"#{job.performer}" with rule "#{job.period.description}" next time will perform at #{job.next}}
+        logger.info %("#{job.performer}" with rule "#{job.period.description}" next time will perform at #{job.next})
       end
     end
 
     def load_rails
       ENV['RACK_ENV'] = ENV['RAILS_ENV'] = config.environment
       require 'rails'
-      require File.expand_path("config/environment.rb")
+      require File.expand_path('config/environment.rb')
       ::Rails.application.eager_load!
       require File.expand_path(config.cronotab)
     end
@@ -75,7 +81,7 @@ module Crono
     end
 
     def start_working_loop
-      while job = Crono.scheduler.next do
+      while (job = Crono.scheduler.next)
         sleep(job.next - Time.now)
         job.perform
       end
diff --git a/lib/crono/config.rb b/lib/crono/config.rb
index a55e694..5569421 100644
--- a/lib/crono/config.rb
+++ b/lib/crono/config.rb
@@ -1,8 +1,9 @@
 module Crono
+  # Crono::Config stores Crono configuration
   class Config
-    CRONOTAB  = "config/cronotab.rb"
-    LOGFILE   = "log/crono.log"
-    PIDFILE   = "tmp/pids/crono.pid"
+    CRONOTAB  = 'config/cronotab.rb'
+    LOGFILE   = 'log/crono.log'
+    PIDFILE   = 'tmp/pids/crono.pid'
 
     attr_accessor :cronotab, :logfile, :pidfile, :daemonize, :environment
 
@@ -11,7 +12,7 @@ module Crono
       self.logfile  = LOGFILE
       self.pidfile  = PIDFILE
       self.daemonize = false
-      self.environment = ENV['RAILS_ENV'] || ENV['RACK_ENV'] || "development"
+      self.environment = ENV['RAILS_ENV'] || ENV['RACK_ENV'] || 'development'
     end
   end
 end
diff --git a/lib/crono/job.rb b/lib/crono/job.rb
index c6ff55a..d3d69e7 100644
--- a/lib/crono/job.rb
+++ b/lib/crono/job.rb
@@ -2,10 +2,12 @@ require 'stringio'
 require 'logger'
 
 module Crono
+  # Crono::Job represents a Crono job
   class Job
     include Logging
 
-    attr_accessor :performer, :period, :last_performed_at, :job_log, :job_logger, :healthy
+    attr_accessor :performer, :period, :last_performed_at, :job_log,
+                  :job_logger, :healthy
 
     def initialize(performer, period)
       self.performer, self.period = performer, period
@@ -36,10 +38,14 @@ module Crono
 
     def save
       @semaphore.synchronize do
-        log = model.reload.log || ""
+        log = model.reload.log || ''
         log << job_log.string
         job_log.truncate(job_log.rewind)
-        model.update(last_performed_at: last_performed_at, log: log, healthy: healthy)
+        model.update(
+          last_performed_at: last_performed_at,
+          log: log,
+          healthy: healthy
+        )
       end
     end
 
@@ -47,20 +53,21 @@ module Crono
       self.last_performed_at = model.last_performed_at
     end
 
-  private
+    private
+
     def perform_job
-      begin
-        performer.new.perform
-      rescue Exception => e
-        log_error "Finished #{performer} in %.2f seconds with error: #{e.message}" % (Time.now - last_performed_at)
-        log_error e.backtrace.join("\n")
-        self.healthy = false
-      else
-        self.healthy = true
-        log "Finished #{performer} in %.2f seconds" % (Time.now - last_performed_at)
-      ensure
-        save
-      end
+      performer.new.perform
+      finished_time_sec = format('%.2f', Time.now - last_performed_at)
+    rescue StandardError => e
+      log_error "Finished #{performer} in #{finished_time_sec} seconds"\
+                "with error: #{e.message}"
+      log_error e.backtrace.join("\n")
+      self.healthy = false
+    else
+      self.healthy = true
+      log "Finished #{performer} in #{finished_time_sec} seconds"
+    ensure
+      save
     end
 
     def log_error(message)
diff --git a/lib/crono/logging.rb b/lib/crono/logging.rb
index 1b94f5f..59becc4 100644
--- a/lib/crono/logging.rb
+++ b/lib/crono/logging.rb
@@ -1,8 +1,9 @@
 module Crono
   mattr_accessor :logger
 
+  # Crono::Logging is a standart Ruby logger wrapper
   module Logging
-    def set_log_to(logfile)
+    def logfile=(logfile)
       Crono.logger = Logger.new(logfile)
     end
 
diff --git a/lib/crono/orm/active_record/crono_job.rb b/lib/crono/orm/active_record/crono_job.rb
index 363cea1..064df4c 100644
--- a/lib/crono/orm/active_record/crono_job.rb
+++ b/lib/crono/orm/active_record/crono_job.rb
@@ -1,8 +1,9 @@
 require 'active_record'
 
 module Crono
+  # Crono::CronoJob is a ActiveRecord model to store job state
   class CronoJob < ActiveRecord::Base
-    self.table_name = "crono_jobs"
+    self.table_name = 'crono_jobs'
     validates :job_id, presence: true, uniqueness: true
   end
 end
diff --git a/lib/crono/performer_proxy.rb b/lib/crono/performer_proxy.rb
index 333081b..2aacab2 100644
--- a/lib/crono/performer_proxy.rb
+++ b/lib/crono/performer_proxy.rb
@@ -1,4 +1,5 @@
 module Crono
+  # PerformerProxy is a proxy used in cronotab.rb semantic
   class PerformerProxy
     def initialize(performer, scheduler)
       @performer = performer
diff --git a/lib/crono/period.rb b/lib/crono/period.rb
index 7a3349d..13c39a3 100644
--- a/lib/crono/period.rb
+++ b/lib/crono/period.rb
@@ -1,4 +1,5 @@
 module Crono
+  # Period describe frequency of performing a task
   class Period
     def initialize(period, at: nil)
       @period = period
@@ -17,7 +18,7 @@ module Crono
 
     def description
       desc = "every #{@period.inspect}"
-      desc += " at %.2i:%.2i" % [@at_hour, @at_min] if @at_hour && @at_min
+      desc += format(' at %.2i:%.2i', @at_hour, @at_min) if @at_hour && @at_min
       desc
     end
 
@@ -29,13 +30,14 @@ module Crono
       when Hash
         return at[:hour], at[:min]
       else
-        raise "Unknown 'at' format"
+        fail "Unknown 'at' format"
       end
     end
 
-  private
+    private
+
     def time_atts
-      {hour: @at_hour, min: @at_min}.compact
+      { hour: @at_hour, min: @at_min }.compact
     end
   end
 end
diff --git a/lib/crono/scheduler.rb b/lib/crono/scheduler.rb
index 0759c1b..4fdad8b 100644
--- a/lib/crono/scheduler.rb
+++ b/lib/crono/scheduler.rb
@@ -1,4 +1,5 @@
 module Crono
+  # Scheduler is a container for job list and queue
   class Scheduler
     attr_accessor :jobs
 
@@ -15,7 +16,8 @@ module Crono
       queue.first
     end
 
-  private
+    private
+
     def queue
       jobs.sort_by(&:next)
     end
diff --git a/lib/crono/web.rb b/lib/crono/web.rb
index 88951ab..fd130c1 100644
--- a/lib/crono/web.rb
+++ b/lib/crono/web.rb
@@ -2,10 +2,11 @@ require 'haml'
 require 'sinatra/base'
 
 module Crono
+  # Web is a Web UI Sinatra app
   class Web < Sinatra::Base
-    set :root, File.expand_path(File.dirname(__FILE__) + "/../../web")
-    set :public_folder, Proc.new { "#{root}/assets" }
-    set :views, Proc.new { "#{root}/views" }
+    set :root, File.expand_path(File.dirname(__FILE__) + '/../../web')
+    set :public_folder, proc { "#{root}/assets" }
+    set :views, proc { "#{root}/views" }
 
     get '/' do
       @jobs = Crono::CronoJob.all
diff --git a/lib/generators/crono/install/install_generator.rb b/lib/generators/crono/install/install_generator.rb
index f103755..df4ff4c 100644
--- a/lib/generators/crono/install/install_generator.rb
+++ b/lib/generators/crono/install/install_generator.rb
@@ -11,8 +11,8 @@ module Crono
         ActiveRecord::Generators::Base.next_migration_number(path)
       end
 
-      desc "Installs crono and generates the necessary configuration files"
-      source_root File.expand_path("../templates", __FILE__)
+      desc 'Installs crono and generates the necessary configuration files'
+      source_root File.expand_path('../templates', __FILE__)
 
       def copy_config
         template 'cronotab.rb.erb', 'config/cronotab.rb'
diff --git a/lib/generators/crono/install/templates/cronotab.rb.erb b/lib/generators/crono/install/templates/cronotab.rb.erb
index 16d3d4e..f6f86bf 100644
--- a/lib/generators/crono/install/templates/cronotab.rb.erb
+++ b/lib/generators/crono/install/templates/cronotab.rb.erb
@@ -7,9 +7,9 @@
 #
 # class TestJob
 #   def perform
-#     puts "Test!"
+#     puts 'Test!'
 #   end
 # end
 #
-# Crono.perform(TestJob).every 2.days, at: "15:30"
+# Crono.perform(TestJob).every 2.days, at: '15:30'
 #
diff --git a/spec/cli_spec.rb b/spec/cli_spec.rb
index b58585d..6e7177d 100644
--- a/spec/cli_spec.rb
+++ b/spec/cli_spec.rb
@@ -1,15 +1,16 @@
-require "spec_helper"
+require 'spec_helper'
 require 'crono/cli'
 
 class TestJob
-  def perform;end
+  def perform
+  end
 end
 
 describe Crono::CLI do
   let(:cli) { Crono::CLI.instance }
 
-  describe "#run" do
-    it "should try to initialize rails with #load_rails and start working loop" do
+  describe '#run' do
+    it 'should initialize rails with #load_rails and start working loop' do
       expect(cli).to receive(:load_rails)
       expect(cli).to receive(:start_working_loop)
       expect(cli).to receive(:parse_options)
@@ -18,34 +19,34 @@ describe Crono::CLI do
     end
   end
 
-  describe "#start_working_loop" do
-    it "should start working loop"
+  describe '#start_working_loop' do
+    it 'should start working loop'
   end
 
-  describe "#parse_options" do
-    it "should set cronotab" do
-      cli.send(:parse_options, ["--cronotab", "/tmp/cronotab.rb"])
-      expect(cli.config.cronotab).to be_eql "/tmp/cronotab.rb"
+  describe '#parse_options' do
+    it 'should set cronotab' do
+      cli.send(:parse_options, ['--cronotab', '/tmp/cronotab.rb'])
+      expect(cli.config.cronotab).to be_eql '/tmp/cronotab.rb'
     end
 
-    it "should set logfile" do
-      cli.send(:parse_options, ["--logfile", "log/crono.log"])
-      expect(cli.config.logfile).to be_eql "log/crono.log"
+    it 'should set logfile' do
+      cli.send(:parse_options, ['--logfile', 'log/crono.log'])
+      expect(cli.config.logfile).to be_eql 'log/crono.log'
     end
 
-    it "should set pidfile" do
-      cli.send(:parse_options, ["--pidfile", "tmp/pids/crono.0.log"])
-      expect(cli.config.pidfile).to be_eql "tmp/pids/crono.0.log"
+    it 'should set pidfile' do
+      cli.send(:parse_options, ['--pidfile', 'tmp/pids/crono.0.log'])
+      expect(cli.config.pidfile).to be_eql 'tmp/pids/crono.0.log'
     end
 
-    it "should set daemonize" do
-      cli.send(:parse_options, ["--daemonize"])
+    it 'should set daemonize' do
+      cli.send(:parse_options, ['--daemonize'])
       expect(cli.config.daemonize).to be true
     end
 
-    it "should set environment" do
-      cli.send(:parse_options, ["--environment", "production"])
-      expect(cli.config.environment).to be_eql("production")
+    it 'should set environment' do
+      cli.send(:parse_options, ['--environment', 'production'])
+      expect(cli.config.environment).to be_eql('production')
     end
   end
 end
diff --git a/spec/config_spec.rb b/spec/config_spec.rb
index df4e247..6726d3c 100644
--- a/spec/config_spec.rb
+++ b/spec/config_spec.rb
@@ -1,15 +1,15 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe Crono::Config do
-  describe "#initialize" do
-    it "should initialize with default configuration options" do
-      ENV["RAILS_ENV"] = "test"
+  describe '#initialize' do
+    it 'should initialize with default configuration options' do
+      ENV['RAILS_ENV'] = 'test'
       @config = Crono::Config.new
       expect(@config.cronotab).to be Crono::Config::CRONOTAB
       expect(@config.logfile).to be Crono::Config::LOGFILE
       expect(@config.pidfile).to be Crono::Config::PIDFILE
       expect(@config.daemonize).to be false
-      expect(@config.environment).to be_eql ENV["RAILS_ENV"]
+      expect(@config.environment).to be_eql ENV['RAILS_ENV']
     end
   end
 end
diff --git a/spec/job_spec.rb b/spec/job_spec.rb
index b5fce77..a638695 100644
--- a/spec/job_spec.rb
+++ b/spec/job_spec.rb
@@ -1,66 +1,67 @@
-require "spec_helper"
+require 'spec_helper'
 
 class TestJob
-  def perform;end
+  def perform
+  end
 end
 
 class TestFailingJob
   def perform
-    raise "Some error"
+    fail 'Some error'
   end
 end
 
 describe Crono::Job do
   let(:period) { Crono::Period.new(2.day) }
-  let(:job) { Crono::Job.new(TestJob, period) } 
+  let(:job) { Crono::Job.new(TestJob, period) }
   let(:failing_job) { Crono::Job.new(TestFailingJob, period) }
 
-  it "should contain performer and period" do
+  it 'should contain performer and period' do
     expect(job.performer).to be TestJob
     expect(job.period).to be period
   end
 
-  describe "#perform" do
+  describe '#perform' do
     after { job.send(:model).destroy }
 
-    it "should run performer in separate thread" do
+    it 'should run performer in separate thread' do
       expect(job).to receive(:save)
       thread = job.perform.join
       expect(thread).to be_stop
     end
 
-    it "should save performin errors to log" do
+    it 'should save performin errors to log' do
       thread = failing_job.perform.join
       expect(thread).to be_stop
       saved_log = Crono::CronoJob.find_by(job_id: failing_job.job_id).log
-      expect(saved_log).to include "Some error"
+      expect(saved_log).to include 'Some error'
     end
 
-    it "should set Job#healthy to true if perform ok" do
-      thread = job.perform.join
+    it 'should set Job#healthy to true if perform ok' do
+      job.perform.join
       expect(job.healthy).to be true
     end
 
-    it "should set Job#healthy to false if perform with error" do
-      thread = failing_job.perform.join
+    it 'should set Job#healthy to false if perform with error' do
+      failing_job.perform.join
       expect(failing_job.healthy).to be false
     end
   end
 
-  describe "#description" do
-    it "should return job identificator" do
-      expect(job.description).to be_eql("Perform TestJob every 2 days")
+  describe '#description' do
+    it 'should return job identificator' do
+      expect(job.description).to be_eql('Perform TestJob every 2 days')
     end
   end
 
-  describe "#save" do
-    it "should save new job to DB" do
+  describe '#save' do
+    it 'should save new job to DB' do
       expect(Crono::CronoJob.where(job_id: job.job_id)).to_not exist
       job.save
       expect(Crono::CronoJob.where(job_id: job.job_id)).to exist
     end
 
-    it "should update saved job" do
+    it 'should update saved job' do
       job.last_performed_at = Time.now
       job.healthy = true
       job.save
@@ -69,8 +70,8 @@ describe Crono::Job do
       expect(@crono_job.healthy).to be true
     end
 
-    it "should save and truncate job log" do
-      message = "test message"
+    it 'should save and truncate job log' do
+      message = 'test message'
       job.send(:log, message)
       job.save
       expect(job.send(:model).reload.log).to include message
@@ -78,37 +79,37 @@ describe Crono::Job do
     end
   end
 
-  describe "#load" do
+  describe '#load' do
     before do
       @saved_last_performed_at = job.last_performed_at = Time.now
       job.save
     end
 
-    it "should load last_performed_at from DB" do
+    it 'should load last_performed_at from DB' do
       @job = Crono::Job.new(TestJob, period)
       @job.load
       expect(@job.last_performed_at.utc.to_s).to be_eql @saved_last_performed_at.utc.to_s
     end
   end
 
-  describe "#log" do
-    it "should write log messages to both common and job log" do
-      message = "Test message"
+  describe '#log' do
+    it 'should write log messages to both common and job log' do
+      message = 'Test message'
       expect(job.logger).to receive(:log).with(Logger::INFO, message)
       expect(job.job_logger).to receive(:log).with(Logger::INFO, message)
       job.send(:log, message)
     end
 
-    it "should write job log to Job#job_log" do
-      message = "Test message"
+    it 'should write job log to Job#job_log' do
+      message = 'Test message'
       job.send(:log, message)
       expect(job.job_log.string).to include(message)
     end
   end
 
-  describe "#log_error" do
-    it "should call log with ERROR severity" do
-      message = "Test message"
+  describe '#log_error' do
+    it 'should call log with ERROR severity' do
+      message = 'Test message'
       expect(job).to receive(:log).with(message, Logger::ERROR)
       job.send(:log_error, message)
     end
diff --git a/spec/orm/active_record/crono_job_spec.rb b/spec/orm/active_record/crono_job_spec.rb
index 8379a6d..85805cf 100644
--- a/spec/orm/active_record/crono_job_spec.rb
+++ b/spec/orm/active_record/crono_job_spec.rb
@@ -1,26 +1,26 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe Crono::CronoJob do
   let(:valid_attrs) do
     {
-      job_id: "Perform TestJob every 3 days"
+      job_id: 'Perform TestJob every 3 days'
     }
   end
 
-  it "should validate presence of job_id" do
-    @crono_job = Crono::CronoJob.new()
+  it 'should validate presence of job_id' do
+    @crono_job = Crono::CronoJob.new
     expect(@crono_job).not_to be_valid
     expect(@crono_job.errors.added?(:job_id, :blank)).to be true
   end
 
-  it "should validate uniqueness of job_id" do
-    Crono::CronoJob.create!(job_id: "TestJob every 2 days")
-    @crono_job = Crono::CronoJob.create(job_id: "TestJob every 2 days")
+  it 'should validate uniqueness of job_id' do
+    Crono::CronoJob.create!(job_id: 'TestJob every 2 days')
+    @crono_job = Crono::CronoJob.create(job_id: 'TestJob every 2 days')
     expect(@crono_job).not_to be_valid
     expect(@crono_job.errors.added?(:job_id, :taken)).to be true
   end
 
-  it "should save job_id to DB" do
+  it 'should save job_id to DB' do
     Crono::CronoJob.create!(valid_attrs)
     @crono_job = Crono::CronoJob.find_by(job_id: valid_attrs[:job_id])
     expect(@crono_job).to be_present
diff --git a/spec/performer_proxy_spec.rb b/spec/performer_proxy_spec.rb
index e0d0673..43eb4c9 100644
--- a/spec/performer_proxy_spec.rb
+++ b/spec/performer_proxy_spec.rb
@@ -1,12 +1,13 @@
-require "spec_helper"
+require 'spec_helper'
 
 class TestJob
-  def perform;end
+  def perform
+  end
 end
 
 describe Crono::PerformerProxy do
-  it "should add job to schedule" do
+  it 'should add job to schedule' do
     expect(Crono.scheduler).to receive(:add_job).with(kind_of(Crono::Job))
-    Crono.perform(TestJob).every(2.days, at: "15:30")
+    Crono.perform(TestJob).every(2.days, at: '15:30')
   end
 end
diff --git a/spec/period_spec.rb b/spec/period_spec.rb
index ed4c73e..f7ac2a2 100644
--- a/spec/period_spec.rb
+++ b/spec/period_spec.rb
@@ -1,4 +1,4 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe Crono::Period do
   around(:each) do |example|
@@ -7,47 +7,48 @@ describe Crono::Period do
     end
   end
 
-  describe "#description" do
-    it "should return period description" do
-      @period = Crono::Period.new(2.day, at: "15:20")
-      expect(@period.description).to be_eql("every 2 days at 15:20")
+  describe '#description' do
+    it 'should return period description' do
+      @period = Crono::Period.new(2.day, at: '15:20')
+      expect(@period.description).to be_eql('every 2 days at 15:20')
     end
   end
 
-  describe "#next" do
-    context "in daily basis" do
-      it "should return the time 2 days from now" do
+  describe '#next' do
+    context 'in daily basis' do
+      it 'should return the time 2 days from now' do
         @period = Crono::Period.new(2.day)
         expect(@period.next).to be_eql(2.day.from_now)
       end
 
       it "should set time to 'at' time as a string" do
         time = 10.minutes.ago
-        @period = Crono::Period.new(2.day, at: [time.hour, time.min].join(':'))
+        at = [time.hour, time.min].join(':')
+        @period = Crono::Period.new(2.day, at: at)
         expect(@period.next).to be_eql(2.day.from_now.change(hour: time.hour, min: time.min))
       end
 
       it "should set time to 'at' time as a hash" do
         time = 10.minutes.ago
-        at = {hour: time.hour, min: time.min}
+        at = { hour: time.hour, min: time.min }
         @period = Crono::Period.new(2.day, at: at)
         expect(@period.next).to be_eql(2.day.from_now.change(at))
       end
 
       it "should raise error when 'at' is wrong" do
         expect {
-          @period = Crono::Period.new(2.day, at: 1)
+          Crono::Period.new(2.day, at: 1)
         }.to raise_error("Unknown 'at' format")
       end
 
-      it "should return time in relation to last time" do
+      it 'should return time in relation to last time' do
         @period = Crono::Period.new(2.day)
         expect(@period.next(since: 1.day.ago)).to be_eql(1.day.from_now)
       end
 
-      it "should return today time if it is first run and not too late" do
+      it 'should return today time if it is first run and not too late' do
         time = 10.minutes.from_now
-        at = {hour: time.hour, min: time.min}
+        at = { hour: time.hour, min: time.min }
         @period = Crono::Period.new(2.day, at: at)
         expect(@period.next.utc.to_s).to be_eql(Time.now.change(at).utc.to_s)
       end
diff --git a/spec/scheduler_spec.rb b/spec/scheduler_spec.rb
index 0828db4..3039f8b 100644
--- a/spec/scheduler_spec.rb
+++ b/spec/scheduler_spec.rb
@@ -1,30 +1,31 @@
-require "spec_helper"
+require 'spec_helper'
 
 class TestJob
-  def perform;end
+  def perform
+  end
 end
 
 describe Crono::Scheduler do
   before(:each) do
     @scheduler = Crono::Scheduler.new
     @jobs = [
-      Crono::Period.new(3.day, at: 10.minutes.from_now.strftime("%H:%M")),
-      Crono::Period.new(1.day, at: 20.minutes.from_now.strftime("%H:%M")),
-      Crono::Period.new(7.day, at: 40.minutes.from_now.strftime("%H:%M"))
+      Crono::Period.new(3.day, at: 10.minutes.from_now.strftime('%H:%M')),
+      Crono::Period.new(1.day, at: 20.minutes.from_now.strftime('%H:%M')),
+      Crono::Period.new(7.day, at: 40.minutes.from_now.strftime('%H:%M'))
     ].map { |period| Crono::Job.new(TestJob, period) }
     @scheduler.jobs = @jobs
   end
 
-  describe "#add_job" do
-    it "should call Job#load on Job" do
-      @job = Crono::Job.new(TestJob, Crono::Period.new(10.day, at: "04:05"))
+  describe '#add_job' do
+    it 'should call Job#load on Job' do
+      @job = Crono::Job.new(TestJob, Crono::Period.new(10.day, at: '04:05'))
       expect(@job).to receive(:load)
       @scheduler.add_job(@job)
     end
   end
 
-  describe "#next" do
-    it "should return next job in schedule" do
+  describe '#next' do
+    it 'should return next job in schedule' do
       expect(@scheduler.next).to be @jobs[0]
     end
   end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 332fd9b..7c37ad7 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -6,9 +6,10 @@ require 'byebug'
 require 'crono'
 require 'generators/crono/install/templates/migrations/create_crono_jobs.rb'
 
-ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: "file::memory:?cache=shared")
+ActiveRecord::Base.establish_connection(
+  adapter: 'sqlite3',
+  database: 'file::memory:?cache=shared'
+)
+
 ActiveRecord::Base.logger = Logger.new(STDOUT)
 CreateCronoJobs.up
-
-RSpec.configure do |config|
-end
diff --git a/spec/web_spec.rb b/spec/web_spec.rb
index 69a2ee3..46ffd89 100644
--- a/spec/web_spec.rb
+++ b/spec/web_spec.rb
@@ -1,44 +1,47 @@
-require "spec_helper"
-require "rack/test"
+require 'spec_helper'
+require 'rack/test'
 include Rack::Test::Methods
 
 describe Crono::Web do
   let(:app) { Crono::Web }
 
   before do
-    @test_job_id = "Perform TestJob every 5 seconds"
-    @test_job_log = "All runs ok"
-    @test_job = Crono::CronoJob.create!(job_id: @test_job_id, log: @test_job_log)
+    @test_job_id = 'Perform TestJob every 5 seconds'
+    @test_job_log = 'All runs ok'
+    @test_job = Crono::CronoJob.create!(
+      job_id: @test_job_id,
+      log: @test_job_log
+    )
   end
 
   after { @test_job.destroy }
 
-  describe "/" do
-    it "should show all jobs" do
+  describe '/' do
+    it 'should show all jobs' do
       get '/'
       expect(last_response).to be_ok
       expect(last_response.body).to include @test_job_id
     end
 
-    it "should show a error mark when a job is unhealthy" do
+    it 'should show a error mark when a job is unhealthy' do
       @test_job.update(healthy: false)
       get '/'
-      expect(last_response.body).to include "Error"
+      expect(last_response.body).to include 'Error'
     end
   end
 
-  describe "/job/:id" do
-    it "should show job log" do
+  describe '/job/:id' do
+    it 'should show job log' do
       get "/job/#{@test_job.id}"
       expect(last_response).to be_ok
       expect(last_response.body).to include @test_job_id
       expect(last_response.body).to include @test_job_log
     end
 
-    it "should show a message about the unhealthy job" do
+    it 'should show a message about the unhealthy job' do
       @test_job.update(healthy: false)
       get "/job/#{@test_job.id}"
-      expect(last_response.body).to include "An error occurs during the last execution of this job"
+      expect(last_response.body).to include 'An error occurs during the last execution of this job'
     end
   end
 end