diff --git a/Gemfile b/Gemfile
--- a/Gemfile
+++ b/Gemfile
@@ -59,15 +59,16 @@
 #syntax highlighter
 gem 'rouge'
 
-#add bootstrap
+#bootstrap add-ons
 gem 'bootstrap-sass', '~> 3.2.0'
 gem 'bootstrap-switch-rails'
 gem 'bootstrap-toggle-rails'
 gem 'autoprefixer-rails'
-
-#bootstrap sortable
 gem 'momentjs-rails'
 gem 'rails_bootstrap_sortable'
+gem 'bootstrap-datepicker-rails'
+gem 'bootstrap3-datetimepicker-rails'
+gem 'jquery-datatables-rails'
 
 #----------- user interface -----------------
 #select 2
diff --git a/Gemfile.lock b/Gemfile.lock
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -61,10 +61,14 @@
     best_in_place (3.0.3)
       actionpack (>= 3.2)
       railties (>= 3.2)
+    bootstrap-datepicker-rails (1.7.1.1)
+      railties (>= 3.0)
     bootstrap-sass (3.2.0.2)
       sass (~> 3.2)
     bootstrap-switch-rails (3.3.3)
     bootstrap-toggle-rails (2.2.1.0)
+    bootstrap3-datetimepicker-rails (4.17.47)
+      momentjs-rails (>= 2.8.1)
     builder (3.2.2)
     coffee-rails (4.2.1)
       coffee-script (>= 2.2.0)
@@ -97,6 +101,11 @@
     i18n (0.7.0)
     in_place_editing (1.2.0)
     jquery-countdown-rails (2.0.2)
+    jquery-datatables-rails (3.4.0)
+      actionpack (>= 3.1)
+      jquery-rails
+      railties (>= 3.1)
+      sass-rails
     jquery-rails (4.2.1)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
@@ -201,9 +210,11 @@
   activerecord-session_store
   autoprefixer-rails
   best_in_place (~> 3.0.1)
+  bootstrap-datepicker-rails
   bootstrap-sass (~> 3.2.0)
   bootstrap-switch-rails
   bootstrap-toggle-rails
+  bootstrap3-datetimepicker-rails
   coffee-rails
   dynamic_form
   fuzzy-string-match
@@ -211,6 +222,7 @@
   haml-rails
   in_place_editing
   jquery-countdown-rails
+  jquery-datatables-rails
   jquery-rails
   jquery-tablesorter
   jquery-timepicker-addon-rails
@@ -232,4 +244,4 @@
   yaml_db
 
 BUNDLED WITH
-   1.13.6
+   1.15.4
diff --git a/app/assets/javascripts/application.js b/app/assets/javascripts/application.js
--- a/app/assets/javascripts/application.js
+++ b/app/assets/javascripts/application.js
@@ -12,10 +12,14 @@
 //
 //= require jquery
 //= require jquery_ujs
+//= require dataTables/jquery.dataTables
+//= require dataTables/bootstrap/3/jquery.dataTables.bootstrap
 //= require jquery-ui
 //= require bootstrap-sprockets
 //= require moment
+//= require moment/th
 //= require bootstrap-sortable
+//= require bootstrap-datetimepicker
 //= require select2
 //= require ace-rails-ap
 //= require ace/mode-c_cpp
@@ -32,6 +36,8 @@
 //= require best_in_place
 //= require best_in_place.jquery-ui
 //= require brython
+//= require bootstrap-datepicker
+//= require bootstrap-datetimepicker
 
 // since this is after blank line, it is not downloaded
 //x= require prototype
diff --git a/app/assets/stylesheets/application.css.scss b/app/assets/stylesheets/application.css.scss
--- a/app/assets/stylesheets/application.css.scss
+++ b/app/assets/stylesheets/application.css.scss
@@ -33,6 +33,9 @@
 //@import bootstrap3-switch
 @import "bootstrap-toggle";
 @import "bootstrap-sortable";
+@import "bootstrap-datepicker3";
+@import "bootstrap-datetimepicker";
+@import "dataTables/bootstrap/3/jquery.dataTables.bootstrap";
 
 //bootstrap navbar color (from)
 $bgDefault: #19197b;
diff --git a/app/controllers/login_controller.rb b/app/controllers/login_controller.rb
--- a/app/controllers/login_controller.rb
+++ b/app/controllers/login_controller.rb
@@ -7,32 +7,38 @@
   end
 
   def login
-    if (!GraderConfiguration['right.bypass_agreement']) and (!params[:accept_agree])
+    user = User.authenticate(params[:login], params[:password])
+    unless user
+      flash[:notice] = 'Wrong password'
+      redirect_to :controller => 'main', :action => 'login'
+      return
+    end
+
+    if (!GraderConfiguration['right.bypass_agreement']) and (!params[:accept_agree]) and !user.admin?
       flash[:notice] = 'You must accept the agreement before logging in'
       redirect_to :controller => 'main', :action => 'login'
-    elsif user = User.authenticate(params[:login], params[:password])
-      session[:user_id] = user.id
-      session[:admin] = user.admin?
+      return
+    end
+
+    #process logging in
+    session[:user_id] = user.id
+    session[:admin] = user.admin?
 
-      # clear forced logout flag for multicontests contest change
-      if GraderConfiguration.multicontests?
-        contest_stat = user.contest_stat
-        if contest_stat.respond_to? :forced_logout
-          if contest_stat.forced_logout
-            contest_stat.forced_logout = false
-            contest_stat.save
-          end
+    # clear forced logout flag for multicontests contest change
+    if GraderConfiguration.multicontests?
+      contest_stat = user.contest_stat
+      if contest_stat.respond_to? :forced_logout
+        if contest_stat.forced_logout
+          contest_stat.forced_logout = false
+          contest_stat.save
         end
       end
-
-      #save login information
-      Login.create(user_id: user.id, ip_address: request.remote_ip)
+    end
 
-      redirect_to :controller => 'main', :action => 'list'
-    else
-      flash[:notice] = 'Wrong password'
-      redirect_to :controller => 'main', :action => 'login'
-    end
+    #save login information
+    Login.create(user_id: user.id, ip_address: request.remote_ip)
+
+    redirect_to :controller => 'main', :action => 'list'
   end
 
   def site_login
diff --git a/app/controllers/problems_controller.rb b/app/controllers/problems_controller.rb
--- a/app/controllers/problems_controller.rb
+++ b/app/controllers/problems_controller.rb
@@ -258,10 +258,7 @@
 
   def change_date_added
     problems = get_problems_from_params
-    year = params[:date_added][:year].to_i
-    month = params[:date_added][:month].to_i
-    day = params[:date_added][:day].to_i
-    date = Date.new(year,month,day)
+    date = Date.parse(params[:date_added])
     problems.each do |p|
       p.date_added = date
       p.save
diff --git a/app/controllers/user_admin_controller.rb b/app/controllers/user_admin_controller.rb
--- a/app/controllers/user_admin_controller.rb
+++ b/app/controllers/user_admin_controller.rb
@@ -24,6 +24,7 @@
       @users = User.paginate :page => params[:page]
       @paginated = true
     end
+    @users = User.all
     @hidden_columns = ['hashed_password', 'salt', 'created_at', 'updated_at']
     @contests = Contest.enabled
   end
diff --git a/app/views/problems/manage.html.haml b/app/views/problems/manage.html.haml
--- a/app/views/problems/manage.html.haml
+++ b/app/views/problems/manage.html.haml
@@ -47,22 +47,26 @@
         What do you want to do to the selected problem?
         %br/
         (You can shift-click to select a range of problems)
-        %ul
+        %ul.form-inline
           %li
             Change date added to
-            = select_date Date.current, :prefix => 'date_added'
+            .input-group.date
+              = text_field_tag :date_added, class: 'form-control'
+              %span.input-group-addon
+                %span.glyphicon.glyphicon-calendar
+            -# = select_date Date.current, :prefix => 'date_added'
             &nbsp;&nbsp;&nbsp;
-            = submit_tag 'Change', :name => 'change_date_added', class: 'btn btn-default'
+            = submit_tag 'Change', :name => 'change_date_added', class: 'btn btn-primary btn-sm'
           %li
             Set available to
-            = submit_tag 'True', :name => 'enable_problem', class: 'btn btn-default'
-            = submit_tag 'False', :name => 'disable_problem', class: 'btn btn-default'
+            = submit_tag 'True', :name => 'enable_problem', class: 'btn btn-primary btn-sm'
+            = submit_tag 'False', :name => 'disable_problem', class: 'btn btn-primary btn-sm'
 
           - if GraderConfiguration.multicontests?
             %li
               Add to 
               = select("contest","id",Contest.all.collect {|c| [c.title, c.id]})
-              = submit_tag 'Add', :name => 'add_to_contest', class: 'btn btn-default'
+              = submit_tag 'Add', :name => 'add_to_contest', class: 'btn btn-primary btn-sm'
           %li
             Add problems to group
             = select_tag "group_id", options_from_collection_for_select( Group.all, 'id','name',params[:group_name]), id: 'group_name',class: 'select2'
@@ -92,3 +96,12 @@
           %td
             - problem.contests.each do |contest|
               = "(#{contest.name} [#{link_to 'x', :action => 'remove_contest', :id => problem.id, :contest_id => contest.id }])"
+
+:javascript
+  $('.input-group.date').datetimepicker({
+    format: 'DD/MMM/YYYY',
+    showTodayButton: true,
+    widgetPositioning: {horizontal: 'auto', vertical: 'bottom'},
+
+  });
+
diff --git a/app/views/problems/stat.html.haml b/app/views/problems/stat.html.haml
--- a/app/views/problems/stat.html.haml
+++ b/app/views/problems/stat.html.haml
@@ -25,9 +25,9 @@
 
 %h2 Submissions
 - if @submissions and @submissions.count > 0
-  %table.info#main_table
+  %table#main_table.table.table-condensed.table-striped
     %thead
-      %tr.info-head
+      %tr
         %th ID
         %th Login
         %th Name
@@ -40,14 +40,18 @@
       - @submissions.each do |sub|
         - next unless sub.user
         - row_odd,curr = !row_odd, sub.user if curr != sub.user
-        %tr{class: row_odd ? "info-odd" : "info-even"}
+        %tr
           %td= link_to sub.id, submission_path(sub)
           %td= link_to sub.user.login, stat_user_path(sub.user)
           %td= sub.user.full_name
-          %td= time_ago_in_words(sub.submitted_at) + " ago"
+          %td{data: {order: sub.submitted_at}}= time_ago_in_words(sub.submitted_at) + " ago"
           %td= sub.points
           %td.fix-width= sub.grader_comment
           %td= sub.ip_address
 - else
   No submission
 
+:javascript
+  $("#main_table").DataTable({
+    paging: false
+  });
diff --git a/app/views/sites/edit.html.haml b/app/views/sites/edit.html.haml
--- a/app/views/sites/edit.html.haml
+++ b/app/views/sites/edit.html.haml
@@ -1,24 +1,35 @@
 %h1 Editing site
 = error_messages_for :site
 = form_for(@site) do |f|
-  %p
-    %b Name
-    %br/
-    = f.text_field :name
-  %p
-    %b Password
-    %br/
-    = f.text_field :password
-  %p
-    %b Started
-    %br/
-    = f.check_box :started
-  %p
-    %b Start time
-    %br/
-    = f.datetime_select :start_time, :include_blank => true
-  %p
-    = f.submit "Update"
+  .row
+    .col-md-4
+      .form-group.field
+        = f.label :name, "Name"
+        = f.text_field :name, class: 'form-control'
+      .form-group.field
+        = f.label :password, "Password"
+        = f.text_field :password, class: 'form-control'
+      .form-group.field
+        = f.label :started, "Started"
+        = f.check_box :started, class: 'form-control'
+      .form-group.field
+        = f.label :start_time, "Start time"
+        -# = f.datetime_select :start_time, :include_blank => true
+        .input-group.date
+          = f.text_field :start_time, class:'form-control' , value: (@site.start_time ? @site.start_time.strftime('%d/%b/%Y %H:%M') : '')
+          %span.input-group-addon
+            %span.glyphicon.glyphicon-calendar
+      .actions
+        = f.submit "Update", class: 'btn btn-primary'
+    .col-md-8
+
 = link_to 'Show', @site
 |
 = link_to 'Back', sites_path
+
+
+:javascript
+  $('.input-group.date').datetimepicker({
+    format: 'DD/MMM/YYYY HH:mm',
+  });
+
diff --git a/app/views/user_admin/index.html.haml b/app/views/user_admin/index.html.haml
--- a/app/views/user_admin/index.html.haml
+++ b/app/views/user_admin/index.html.haml
@@ -1,4 +1,4 @@
-%h1 Listing users
+%h1 Users
 
 .panel.panel-primary
   .panel-title.panel-heading
@@ -41,8 +41,8 @@
 %p
   = link_to '+ New user', { :action => 'new' }, { class: 'btn btn-success '}
   = link_to '+ New list of users', { :action => 'new_list' }, { class: 'btn btn-success '}
+  = link_to 'Bulk Manage', bulk_manage_user_admin_path , { class: 'btn btn-default btn-info'}
   = link_to 'View administrators',{ :action => 'admin'}, { class: 'btn btn-default '}
-  = link_to 'Bulk Manage', bulk_manage_user_admin_path , { class: 'btn btn-default '}
   = link_to 'Random passwords',{ :action => 'random_all_passwords'}, { class: 'btn btn-default '}
   = link_to 'View active users',{ :action => 'active'}, { class: 'btn btn-default '}
   = link_to 'Mass mailing',{ :action => 'mass_mailing'}, { class: 'btn btn-default '}
@@ -56,17 +56,17 @@
     = link_to "[#{contest.name}]", :action => 'contests', :id => contest.id
   = link_to "[no contest]", :action => 'contests', :id => 'none'
 
-Total #{@user_count} users |
-- if !@paginated
-  Display all users.
-  \#{link_to '[show in pages]', :action => 'index', :page => '1'}
-- else
-  Display in pages.
-  \#{link_to '[display all]', :action => 'index', :page => 'all'} |
-  \#{will_paginate @users, :container => false}
+-# Total #{@user_count} users |
+-# - if !@paginated
+-#   Display all users.
+-#   \#{link_to '[show in pages]', :action => 'index', :page => '1'}
+-# - else
+-#   Display in pages.
+-#   \#{link_to '[display all]', :action => 'index', :page => 'all'} |
+-#   \#{will_paginate @users, :container => false}
 
 
-%table.table.table-hover.table-condense
+%table.table.table-hover.table-condense.datatable
   %thead
     %th Login
     %th Full name
@@ -99,3 +99,8 @@
 %br/
 = link_to '+ New user', { :action => 'new' }, { class: 'btn btn-success '}
 = link_to '+ New list of users', { :action => 'new_list' }, { class: 'btn btn-success '}
+
+:javascript
+  $('.datatable').DataTable({
+    'pageLength': 50
+  });
diff --git a/app/views/users/stat.html.haml b/app/views/users/stat.html.haml
--- a/app/views/users/stat.html.haml
+++ b/app/views/users/stat.html.haml
@@ -36,7 +36,7 @@
 =render partial: 'application/bar_graph', locals: {histogram: @histogram, param: {bar_width: 7}}
 
 
-%table.tablesorter-cafe#submission_table
+%table#submission_table.table.table-striped
   %thead
     %tr
       %th ID
@@ -64,3 +64,7 @@
 
 
 
+:javascript
+  $("#submission_table").DataTable({
+    paging: false
+  });