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
@@ -187,7 +187,7 @@
   end
 
   def do_manage
-    if params.has_key? 'change_date_added'
+    if params.has_key? 'change_date_added' and params[:date_added].strip.empty? == false
       change_date_added
     elsif params.has_key? 'add_to_contest'
       add_to_contest
diff --git a/app/controllers/report_controller.rb b/app/controllers/report_controller.rb
--- a/app/controllers/report_controller.rb
+++ b/app/controllers/report_controller.rb
@@ -43,7 +43,7 @@
     end
 
     #users
-    @users = if params[:user] == "all" then 
+    @users = if params[:users] == "all" then 
                User.includes(:contests).includes(:contest_stat)
              else 
                User.includes(:contests).includes(:contest_stat).where(enabled: true)
diff --git a/app/models/submission.rb b/app/models/submission.rb
--- a/app/models/submission.rb
+++ b/app/models/submission.rb
@@ -8,7 +8,7 @@
   before_validation :assign_language
 
   validates_presence_of :source
-  validates_length_of :source, :maximum => 100_000, :allow_blank => true, :message => 'too long'
+  validates_length_of :source, :maximum => 100_000, :allow_blank => true, :message => 'code too long, the limit is 100,000 bytes'
   validates_length_of :source, :minimum => 1, :allow_blank => true, :message => 'too short'
   validate :must_have_valid_problem
   validate :must_specify_language
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
@@ -110,6 +110,7 @@
   $('.input-group.date').datetimepicker({
     format: 'DD/MMM/YYYY',
     showTodayButton: true,
+    locale: 'en',
     widgetPositioning: {horizontal: 'auto', vertical: 'bottom'},
 
   });
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
@@ -31,6 +31,7 @@
 :javascript
   $('.input-group.date').datetimepicker({
     format: 'DD/MMM/YYYY HH:mm',
+    locale: 'en',
     showTodayButton: true,
   });
 
diff --git a/db/migrate/20180612102327_change_submission_source_size.rb b/db/migrate/20180612102327_change_submission_source_size.rb
new file mode 100644
--- /dev/null
+++ b/db/migrate/20180612102327_change_submission_source_size.rb
@@ -0,0 +1,5 @@
+class ChangeSubmissionSourceSize < ActiveRecord::Migration
+  def change
+    change_column :submissions, :source, :text, :limit => 1.megabyte
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170914150742) do
+ActiveRecord::Schema.define(version: 20180612102327) do
 
   create_table "announcements", force: :cascade do |t|
     t.string   "author",       limit: 255
@@ -209,7 +209,7 @@
     t.integer  "user_id",               limit: 4
     t.integer  "problem_id",            limit: 4
     t.integer  "language_id",           limit: 4
-    t.text     "source",                limit: 65535
+    t.text     "source",                limit: 16777215
     t.binary   "binary",                limit: 65535
     t.datetime "submitted_at"
     t.datetime "compiled_at"