diff --git a/README.md b/README.md
index 2c8a055..0b50d72 100644
--- a/README.md
+++ b/README.md
@@ -33,4 +33,4 @@ You can setup options in administration menu.
 
 ## Compatibility
 
-This version supports redmine 3.x.
+This version supports redmine 4.x.
diff --git a/app/controllers/reminder_configuration_controller.rb b/app/controllers/reminder_configuration_controller.rb
index ab289b0..235bbde 100644
--- a/app/controllers/reminder_configuration_controller.rb
+++ b/app/controllers/reminder_configuration_controller.rb
@@ -3,7 +3,7 @@ class ReminderConfigurationController < ApplicationController
 
   layout 'admin'
 
-  before_filter :require_admin
+  before_action :require_admin
 
   def edit
     @configuration = ReminderConfiguration.instance
@@ -23,7 +23,7 @@ def update
   def permitted_conf_params
     params.required(:reminder_configuration).permit(
       :days, :issue_status_selector, :project_selector, :tracker_selector, :send_to_author,
-      :send_to_assigned_to, :send_to_watcher, :send_to_custom_user,
+      :send_to_assigned_to, :use_due_day, :send_to_watcher, :send_to_custom_user,
       { issue_status_ids: [] },
       { project_ids: [] },
       { tracker_ids: [] }
diff --git a/app/models/reminder_all_mailer.rb b/app/models/reminder_all_mailer.rb
index 7572c49..f11d0ef 100644
--- a/app/models/reminder_all_mailer.rb
+++ b/app/models/reminder_all_mailer.rb
@@ -1,7 +1,7 @@
 class ReminderAllMailer < Mailer
   helper :reminder_all
 
-  def reminder_all(user, assigned_issues, auth_issues, watched_issues, custom_user_issues, days)
+  def reminder_all(user, assigned_issues, auth_issues, watched_issues, custom_user_issues, without_due_day, days)
     recipients          = user.mail
     day_tag             = [l(:mail_reminder_all_day1), l(:mail_reminder_all_day2),
       l(:mail_reminder_all_day2), l(:mail_reminder_all_day2),
@@ -25,6 +25,7 @@ def reminder_all(user, assigned_issues, auth_issues, watched_issues, custom_user
     @auth_issues        = auth_issues
     @watched_issues     = watched_issues
     @custom_user_issues = custom_user_issues
+    @without_due_day    = without_due_day
     @days               = days
     @issues_url         = url_for(
       controller: 'issues',
@@ -35,9 +36,9 @@ def reminder_all(user, assigned_issues, auth_issues, watched_issues, custom_user
     mail to: recipients, subject: subject
   end
 
-  def self.deliver_reminder_all_if_any(user, assigned_issues, auth_issues, watched_issues, custom_user_issues, days)
-    issues_count = (assigned_issues + auth_issues + watched_issues + custom_user_issues).uniq.size
+  def self.deliver_reminder_all_if_any(user, assigned_issues, auth_issues, watched_issues, custom_user_issues, without_due_day, days)
+    issues_count = (assigned_issues + auth_issues + watched_issues + custom_user_issues + without_due_day).uniq.size
     reminder_all(user, assigned_issues, auth_issues, watched_issues,
-      custom_user_issues, days).deliver if issues_count > 0
+      custom_user_issues, without_due_day, days).deliver_later if issues_count > 0
   end
 end
diff --git a/app/models/reminder_configuration.rb b/app/models/reminder_configuration.rb
index 2665d62..72274c4 100644
--- a/app/models/reminder_configuration.rb
+++ b/app/models/reminder_configuration.rb
@@ -53,6 +53,7 @@ def set_default_values
     self.send_to_assigned_to   = true if self.send_to_assigned_to.nil?
     self.send_to_watcher       = true if self.send_to_watcher.nil?
     self.send_to_custom_user   ||= false
+    self.use_due_day           ||= false
     true
   end
 end
diff --git a/app/views/reminder_all_mailer/reminder_all.html.erb b/app/views/reminder_all_mailer/reminder_all.html.erb
index c27851b..6b66162 100644
--- a/app/views/reminder_all_mailer/reminder_all.html.erb
+++ b/app/views/reminder_all_mailer/reminder_all.html.erb
@@ -14,4 +14,8 @@
     issues:  @custom_user_issues,
     message: l_mail_body_reminder_custom_user(@custom_user_issues.size, @days) } %>
 
+<%= render partial: 'issues', locals: {
+    issues:  @without_due_day,
+    message: l(:mail_body_reminder_assigned_set, @without_due_day.size) } %>
+
 <p><%= link_to l(:label_issue_view_all), @issues_url %></p>
diff --git a/app/views/reminder_all_mailer/reminder_all.text.erb b/app/views/reminder_all_mailer/reminder_all.text.erb
index c06f6d4..deb3e6b 100644
--- a/app/views/reminder_all_mailer/reminder_all.text.erb
+++ b/app/views/reminder_all_mailer/reminder_all.text.erb
@@ -14,4 +14,8 @@
     issues:  @custom_user_issues,
     message: l_mail_body_reminder_custom_user(@custom_user_issues.size, @days) } %>
 
+<%= render partial: 'issues', locals: {
+    issues:  @without_due_day,
+    message: l(:mail_body_reminder_assigned_set, @without_due_day.size) } %>
+
 <%= @issues_url %>
diff --git a/app/views/reminder_configuration/edit.html.erb b/app/views/reminder_configuration/edit.html.erb
index 38524bd..88ef213 100644
--- a/app/views/reminder_configuration/edit.html.erb
+++ b/app/views/reminder_configuration/edit.html.erb
@@ -39,6 +39,10 @@
 
   <%= f.check_box :send_to_author %>
   <%= f.label :send_to_author, l(:field_author) %>
+  <br/>
+
+   <%= f.check_box :use_due_day %>
+  <%= f.label :use_due_day, l(:field_use_due_day) %>
   <br/>
 
   <%= f.check_box :send_to_assigned_to %>
diff --git a/assets/javascripts/reminder_configuration.js b/assets/javascripts/reminder_configuration.js
index cc90b99..c7eae00 100644
--- a/assets/javascripts/reminder_configuration.js
+++ b/assets/javascripts/reminder_configuration.js
@@ -1,13 +1,13 @@
 var toggleExplicitList = function(selector, list, explicit_value) {
   var fnToggleList = function() {
-    if ($(selector).getValue() == explicit_value) {
+    if ($(selector).val() == explicit_value) {
       $(list).show();
     } else {
       $(list).hide();
     }
   };
 
-  $(selector).observe('change', fnToggleList);
+  $(selector).on('change', fnToggleList);
 
   fnToggleList();
 };
diff --git a/config/locales/en.yml b/config/locales/en.yml
index fc063c2..1a53d18 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -17,6 +17,7 @@ en:
   mail_body_reminder_assigned5: "%{count} issues that are assigned to you are due in the next %{days} %{day}:"
   mail_body_reminder_watched5: "%{count} issues that are watched by you are due in the next %{days} %{day}:"
   mail_body_reminder_custom_user5: "%{count} issues in which you are mentioned are due in the next %{days} %{day}:"
+  mail_body_reminder_assigned_set: "%{count} issues that are assigned to you which don't have end date set:"
 
   label_reminder_options: "Reminder options"
   label_criteria_task: "Criteria task"
@@ -37,3 +38,4 @@ en:
       explicit: "tasks from selected trackers"
 
   field_custom_user: "User from custom field"
+  field_use_due_day: "Send tasks which have end date only"
diff --git a/config/locales/pl.yml b/config/locales/pl.yml
new file mode 100644
index 0000000..4d38a92
--- /dev/null
+++ b/config/locales/pl.yml
@@ -0,0 +1,39 @@
+pl:
+  mail_reminder_all_day1: "dnia"
+  mail_reminder_all_day2: "dni"
+  mail_reminder_all_day5: "dni"
+  mail_subject_reminder_all1: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}"
+  mail_body_reminder_auth1: "%{count} zadań do wykonania w ciągu %{days} %{day}, których jesteś autorem:"
+  mail_body_reminder_assigned1: "%{count} zadań do wykonania w ciągu %{days} %{day}, do których jesteś przypisany:"
+  mail_body_reminder_watched1: "%{count} zadań do wykonania w ciągu %{days} %{day}, których jesteś obserwatorem:"
+  mail_body_reminder_custom_user1: "%{count} zadań do wykonania w ciągu %{days} %{day}, w których o Tobie wspomniano:"
+  mail_subject_reminder_all2: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}"
+  mail_body_reminder_auth2: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}, których jesteś autorem:"
+  mail_body_reminder_assigned2: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}, do których jesteś przypisany:"
+  mail_body_reminder_watched2: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}, których jesteś obserwatorem:"
+  mail_body_reminder_custom_user2: "%{count} issues in which you are mentioned are due in the next %{days} %{day}:"
+  mail_subject_reminder_all5: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}"
+  mail_body_reminder_auth5: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}, których jesteś autorem:"
+  mail_body_reminder_assigned5: "%{count} issues that are assigned to you are due in the next %{days} %{day}:"
+  mail_body_reminder_watched5: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}, których jesteś obserwatorem:"
+  mail_body_reminder_custom_user5: "%{count} zadań do wykonania w ciągu następnych %{days} %{day}, w których o Tobie wspomniano:"
+
+  label_reminder_options: "Przypominacz - ustawienia"
+  label_criteria_task: "Kryteria zadania"
+  label_completion_date: "Data ukończenia"
+  label_tasks_due_in: "Zadania, które muszą być ukończonew ciągu następnych"
+  label_days: "Dni"
+  label_reminder_recipients: "Odbiorcy przypominacza"
+
+  redmine_reminder:
+    issue_statuses:
+      all_opened: "Wszystkie otwarte zadania"
+      explicit: "Zadania z wybranym statusem"
+    projects:
+      all: "Zadania ze wszystkich projektów"
+      explicit: "Zadania z wybranych projektów"
+    trackers:
+      all: "Zadania każdego typu"
+      explicit: "Wybrane typy zadań"
+
+  field_custom_user: "Użytkownik z pola niestandardowego"
diff --git a/db/migrate/20120911151845_create_reminder_configurations.rb b/db/migrate/20120911151845_create_reminder_configurations.rb
index cb523e4..1e579a8 100644
--- a/db/migrate/20120911151845_create_reminder_configurations.rb
+++ b/db/migrate/20120911151845_create_reminder_configurations.rb
@@ -1,4 +1,4 @@
-class CreateReminderConfigurations < ActiveRecord::Migration
+class CreateReminderConfigurations < ActiveRecord::Migration[5.1]
   def self.up
     create_table :reminder_configurations do |t|
       t.column :days, :integer
diff --git a/db/migrate/20120911164322_create_reminder_projects.rb b/db/migrate/20120911164322_create_reminder_projects.rb
index 0f9b937..57816af 100644
--- a/db/migrate/20120911164322_create_reminder_projects.rb
+++ b/db/migrate/20120911164322_create_reminder_projects.rb
@@ -1,4 +1,4 @@
-class CreateReminderProjects < ActiveRecord::Migration
+class CreateReminderProjects < ActiveRecord::Migration[5.1]
   def self.up
     create_table :reminder_projects do |t|
       t.column :reminder_configuration_id, :integer
diff --git a/db/migrate/20120911164358_create_reminder_issue_statuses.rb b/db/migrate/20120911164358_create_reminder_issue_statuses.rb
index ef7fdc2..8b613e3 100644
--- a/db/migrate/20120911164358_create_reminder_issue_statuses.rb
+++ b/db/migrate/20120911164358_create_reminder_issue_statuses.rb
@@ -1,4 +1,4 @@
-class CreateReminderIssueStatuses < ActiveRecord::Migration
+class CreateReminderIssueStatuses < ActiveRecord::Migration[5.1]
   def self.up
     create_table :reminder_issue_statuses do |t|
       t.column :reminder_configuration_id, :integer
diff --git a/db/migrate/20120918093621_create_reminder_trackers.rb b/db/migrate/20120918093621_create_reminder_trackers.rb
index 14ef362..e07d1d2 100644
--- a/db/migrate/20120918093621_create_reminder_trackers.rb
+++ b/db/migrate/20120918093621_create_reminder_trackers.rb
@@ -1,4 +1,4 @@
-class CreateReminderTrackers < ActiveRecord::Migration
+class CreateReminderTrackers < ActiveRecord::Migration[5.1]
   def self.up
     create_table :reminder_trackers do |t|
       t.column :reminder_configuration_id, :integer
diff --git a/db/migrate/20120918095158_add_tracker_selector_to_reminder_configurations.rb b/db/migrate/20120918095158_add_tracker_selector_to_reminder_configurations.rb
index 43915da..758678d 100644
--- a/db/migrate/20120918095158_add_tracker_selector_to_reminder_configurations.rb
+++ b/db/migrate/20120918095158_add_tracker_selector_to_reminder_configurations.rb
@@ -1,4 +1,4 @@
-class AddTrackerSelectorToReminderConfigurations < ActiveRecord::Migration
+class AddTrackerSelectorToReminderConfigurations < ActiveRecord::Migration[5.1]
   def self.up
     unless column_exists? :reminder_configurations, :tracker_selector
       add_column :reminder_configurations, :tracker_selector, :string
diff --git a/db/migrate/20170624100352_add_use_due_day_to_reminder_configuration.rb b/db/migrate/20170624100352_add_use_due_day_to_reminder_configuration.rb
new file mode 100644
index 0000000..c11c688
--- /dev/null
+++ b/db/migrate/20170624100352_add_use_due_day_to_reminder_configuration.rb
@@ -0,0 +1,5 @@
+class AddUseDueDayToReminderConfiguration < ActiveRecord::Migration[5.1]
+  def change
+    add_column :reminder_configurations, :use_due_day, :boolean, default: false
+  end
+end
diff --git a/init.rb b/init.rb
index e243884..e74ebf6 100644
--- a/init.rb
+++ b/init.rb
@@ -11,7 +11,7 @@
   menu :admin_menu,
     :reminder_options,
     { controller: 'reminder_configuration', action: 'edit' },
-    html: { class: 'reminder_options_label' }
+    html: { class: 'icon reminder_options_label' }
 end
 
 require_dependency 'redmine_reminder/hooks'
diff --git a/lib/redmine_reminder/collector.rb b/lib/redmine_reminder/collector.rb
index 90ed49c..a1bd967 100644
--- a/lib/redmine_reminder/collector.rb
+++ b/lib/redmine_reminder/collector.rb
@@ -5,28 +5,41 @@ def initialize(options)
     @options = options
   end
 
+  def logger
+	Rails.logger
+  end
+  
   def collect_reminders
     reminders = {}
 
-    issues = issues_due_in_days
-    issues.each do |issue|
+    issues = if options.use_due_day?
+               issues_due_in_days(true)
+             else
+               issues_due_in_days(false)
+             end
 
+	# logger.info issues.count()
+    issues.each do |issue|
       if options.send_to_author?
         reminders[issue.author] ||=
-          RedmineReminder::Reminder.new(issue.author)
+            RedmineReminder::Reminder.new(issue.author)
         reminders[issue.author][:author] << issue
       end
 
-      if options.send_to_assigned_to? && issue.assigned_to
+      if options.send_to_assigned_to? && issue.assigned_to && issue.due_date
         reminders[issue.assigned_to] ||=
-          RedmineReminder::Reminder.new(issue.assigned_to)
+            RedmineReminder::Reminder.new(issue.assigned_to)
         reminders[issue.assigned_to][:assigned_to] << issue
+		#logger.info "v=#{issue}"
+		#logger.info "v.author=#{issue.author}"
+		#logger.info "v.assigned_to=#{issue.assigned_to}"
+		#logger.info "v.due_date=#{issue.due_date}"
       end
 
       if options.send_to_watcher?
         issue.watchers.each do |watcher|
           reminders[watcher.user] ||=
-            RedmineReminder::Reminder.new(watcher.user)
+              RedmineReminder::Reminder.new(watcher.user)
           reminders[watcher.user][:watcher] << issue
         end
       end
@@ -34,27 +47,52 @@ def collect_reminders
       if options.send_to_custom_user?
         issue_custom_users(issue).each do |custom_user|
           reminders[custom_user] ||=
-            RedmineReminder::Reminder.new(custom_user)
+              RedmineReminder::Reminder.new(custom_user)
           reminders[custom_user][:custom_user] << issue
         end
+      end
+
+	  if !options.use_due_day? && issue.assigned_to && !issue.due_date
+		#logger.info "v=#{issue}"
+		#logger.info "v.author=#{issue.author}"
+		#logger.info "v.assigned_to=#{issue.assigned_to}"
+		#logger.info "v.due_date=#{issue.due_date}"
+        reminders[issue.assigned_to] ||=
+            RedmineReminder::Reminder.new(issue.assigned_to)
+        reminders[issue.assigned_to][:without_due_day] << issue
       end
     end
     reminders.values.map &:uniq!
     reminders.values || []
+	
+	#reminders.values.each do |v|
+	#	logger.info "v=#{v}"
+	#	logger.info "v.user=#{v.user}"
+	#end
+	
   end
 
   private
 
   # Get issues due in X days
-  def issues_due_in_days
+  def issues_due_in_days(use_due_day = true)
     due_date      = options.days.day.from_now.to_date
-    sql_condition = ARCondition.new ["#{Issue.table_name}.due_date <= ?", due_date]
+    sql_condition = if use_due_day
+                      ARCondition.new ["#{Issue.table_name}.due_date <= ?", due_date]
+                    else
+                      ARCondition.new ["#{Issue.table_name}.due_date <= ? OR #{Issue.table_name}.due_date IS NULL", due_date]
+                    end
+
     sql_condition << issue_statuses
     sql_condition << projects
     sql_condition << trackers
-    Issue.joins(:status, :assigned_to, :author, :project, :watchers, :tracker).
-      where(sql_condition.conditions).
-      order("#{Issue.table_name}.due_date, #{Project.table_name}.name")
+    scope = Issue.includes(:status, :assigned_to, :author, :project, :watchers, :tracker)
+    if Redmine::VERSION::MAJOR>=3
+      scope = scope.references(:status, :assigned_to, :author, :project, :watchers, :tracker)
+    end
+
+    scope.where(sql_condition.conditions).
+        order("#{Project.table_name}.name, #{Issue.table_name}.due_date")
   end
 
   def issue_statuses
diff --git a/lib/tasks/reminder_all.rake b/lib/tasks/reminder_all.rake
index d5fe745..f5ebe69 100644
--- a/lib/tasks/reminder_all.rake
+++ b/lib/tasks/reminder_all.rake
@@ -30,16 +30,26 @@ namespace :redmine do
 
     collector = RedmineReminder::Collector.new(options)
     collector.collect_reminders.each do |r|
-      next unless r.user.active?
+      users = if r.user.is_a?(User)
+                [r.user]
+              else
+                r.user.users
+              end
+      users = users.compact.select{|u| u.active?}
+      next unless users.blank?
       ReminderAllMailer.with_synched_deliveries do
-        ReminderAllMailer.deliver_reminder_all_if_any(
-            r.user,
-            r[:assigned_to],
-            r[:author],
-            r[:watcher],
-            r[:custom_user],
-            options.days
-        )
+          users.each do |user|
+            ReminderAllMailer.deliver_reminder_all_if_any(
+              user,
+              r[:assigned_to],
+              r[:author],
+              r[:watcher],
+              r[:custom_user],
+              r[:without_due_day],
+              options.days
+            )
+          end
+
       end
     end
   end