Index: app/models/mailer.rb
===================================================================
--- app/models/mailer.rb	2011-07-02 07:13:36.000000000 +0200
+++ app/models/mailer.rb	2011-07-17 17:19:25.000000000 +0200
@@ -78,14 +78,14 @@
     render_multipart('issue_edit', body)
   end
 
-  def reminder(user, issues, days)
+  def reminder(user, issues, days, start, sort_key)
     redmine_headers 'Type' => "Issue"
     set_language_if_valid user.language
     recipients user.mail
     subject l(:mail_subject_reminder, :count => issues.size, :days => days)
     body :issues => issues,
          :days => days,
-         :issues_url => url_for(:controller => 'issues', :action => 'index', :set_filter => 1, :assigned_to_id => user.id, :sort => 'due_date:asc')
+         :issues_url => url_for(:controller => 'issues', :action => 'index', :set_filter => 1, :assigned_to_id => user.id, :sort => "#{sort_key}:asc")
     render_multipart('reminder', body)
   end
 
@@ -345,18 +345,26 @@
     tracker = options[:tracker] ? Tracker.find(options[:tracker]) : nil
     user_ids = options[:users]
 
-    s = ARCondition.new ["#{IssueStatus.table_name}.is_closed = ? AND #{Issue.table_name}.due_date <= ?", false, days.day.from_now.to_date]
+    start = options[:start] || nil
+    if start
+        s = ARCondition.new ["#{IssueStatus.table_name}.is_closed = ? AND #{Issue.table_name}.start_date = ?", false, days.day.from_now.to_date]
+        sort_key = "start_date"
+    else
+        s = ARCondition.new ["#{IssueStatus.table_name}.is_closed = ? AND ((#{Issue.table_name}.due_date IS NULL AND #{Version.table_name}.effective_date <= ?) OR #{Issue.table_name}.due_date <= ?)", false, days.day.from_now.to_date, days.day.from_now.to_date]
+        sort_key = "due_date"
+    end
+
     s << "#{Issue.table_name}.assigned_to_id IS NOT NULL"
     s << ["#{Issue.table_name}.assigned_to_id IN (?)", user_ids] if user_ids.present?
     s << "#{Project.table_name}.status = #{Project::STATUS_ACTIVE}"
     s << "#{Issue.table_name}.project_id = #{project.id}" if project
     s << "#{Issue.table_name}.tracker_id = #{tracker.id}" if tracker
 
-    issues_by_assignee = Issue.find(:all, :include => [:status, :assigned_to, :project, :tracker],
+    issues_by_assignee = Issue.find(:all, :include => [:status, :assigned_to, :project, :tracker, :fixed_version],
                                           :conditions => s.conditions
                                     ).group_by(&:assigned_to)
     issues_by_assignee.each do |assignee, issues|
-      deliver_reminder(assignee, issues, days) if assignee && assignee.active?
+      deliver_reminder(assignee, issues, days, start, sort_key) if assignee && assignee.active?
     end
   end

--- lib/tasks/reminder.rake    2010-09-27 00:32:38.000000000 +0200
+++ lib/tasks/reminder.rake    2010-10-14 22:57:11.000000000 +0200
@@ -22,6 +22,7 @@
   * days     => number of days to remind about (defaults to 7)
   * tracker  => id of tracker (defaults to all trackers)
   * project  => id or identifier of project (defaults to all projects)
+  * start    => remind at for start-date instead of due-date
   * users    => comma separated list of user ids who should be reminded
 
 Example:
@@ -34,6 +35,7 @@
     options[:days] = ENV['days'].to_i if ENV['days']
     options[:project] = ENV['project'] if ENV['project']
     options[:tracker] = ENV['tracker'].to_i if ENV['tracker']
+    options[:start] = ENV['start'].to_i if ENV['start']
     options[:users] = (ENV['users'] || '').split(',').each(&:strip!)
     
     Mailer.reminders(options)