Redmine/app/views/projects/calendar.rhtml

<% cache(:year => @year, :month => @month, :tracker_ids => @selected_tracker_ids, :subprojects => params[:with_subprojects], :lang => current_language) do %>
<h2><%= l(:label_calendar) %>: <%= "#{month_name(@month).downcase} #{@year}" %></h2>

<table width="100%">
<tr><td align="left">
    <%= link_to_remote ('&#171; ' + (@month==1 ? "#{month_name(12)} #{@year-1}" : "#{month_name(@month-1)}")), 
                        {:update => "content", :url => { :year => (@month==1 ? @year-1 : @year), :month =>(@month==1 ? 12 : @month-1), :tracker_ids => @selected_tracker_ids, :with_subprojects => params[:with_subprojects] }},
                        {:href => url_for(:action => 'calendar', :year => (@month==1 ? @year-1 : @year), :month =>(@month==1 ? 12 : @month-1), :tracker_ids => @selected_tracker_ids, :with_subprojects => params[:with_subprojects])}
                        %>
</td><td align="right">
    <%= link_to_remote ((@month==12 ? "#{month_name(1)} #{@year+1}" : "#{month_name(@month+1)}") + ' &#187;'), 
                        {:update => "content", :url => { :year => (@month==12 ? @year+1 : @year), :month =>(@month==12 ? 1 : @month+1), :tracker_ids => @selected_tracker_ids, :with_subprojects => params[:with_subprojects] }},
                        {:href => url_for(:action => 'calendar', :year => (@month==12 ? @year+1 : @year), :month =>(@month==12 ? 1 : @month+1), :tracker_ids => @selected_tracker_ids, :with_subprojects => params[:with_subprojects])}
                        %>
</td></tr>
</table>

<table class="cal">
<thead>
<tr>
<td></td>
<% 1.upto(7) do |d| %>
    <th style="width:14%"><%= day_name(d) %></th>
<% end %>
</tr>
</thead>
<tbody>
<tr style="height:100px">
<% day = @date_from
while day <= @date_to
	if day.cwday == 1 %>
	<th><%= day.cweek %></th>
	<% end %>	
	<td valign="top" class="<%= day.month==@month ? "even" : "odd" %> <%= Date.today == day ? 'today' : '' %>" style="width:14%;">
	<p class="textright"><%= day==Date.today ? "<b>#{day.day}</b>" : day.day %></p>	
	<% ((@ending_events_by_days[day] || []) + (@starting_events_by_days[day] || [])).uniq.each do |i| %>
	    <% if i.is_a? Issue %>
	    <div class="tooltip">
		<%= if day == i.start_date and day == i.due_date
		    image_tag('arrow_bw.png')
		elsif day == i.start_date
		    image_tag('arrow_from.png') 
		elsif day == i.due_date
		    image_tag('arrow_to.png') 
		end %>
		<small>
		<%= h("#{i.project.name} -") unless @project && @project == i.project %>
		<%= link_to_issue i %>:
        <%= h(truncate(i.subject, 30)) %>
		</small>
        <span class="tip">
        <%= render :partial => "issues/tooltip", :locals => { :issue => i }%>
        </span>		
		</div>
		<% else %>
        <small><%= link_to_version i, :class => "icon icon-package" %></small>
		<% end %>
	<% end %>
    </td>
	<%= '</tr><tr style="height:100px">' if day.cwday >= 7 and day!=@date_to %>
	<%
	day = day + 1
end %>
</tr>
</tbody>
</table>

<%= image_tag 'arrow_from.png' %>&nbsp;&nbsp;<%= l(:text_tip_task_begin_day) %><br />
<%= image_tag 'arrow_to.png' %>&nbsp;&nbsp;<%= l(:text_tip_task_end_day) %><br />
<%= image_tag 'arrow_bw.png' %>&nbsp;&nbsp;<%= l(:text_tip_task_begin_end_day) %><br />
<% end %>

<% content_for :sidebar do %>
    <h3><%= l(:label_calendar) %></h3>
    
    <% form_tag() do %>
    <p><%= select_month(@month, :prefix => "month", :discard_type => true) %>
    <%= select_year(@year, :prefix => "year", :discard_type => true) %></p>
    
    <% @trackers.each do |tracker| %>
      <%= check_box_tag "tracker_ids[]", tracker.id, (@selected_tracker_ids.include? tracker.id.to_s) %> <%= tracker.name %><br />
    <% end %>
    <% if @project.active_children.any? %>
    <br /><%= check_box_tag "with_subprojects", 1, params[:with_subprojects] %> <%=l(:label_subproject_plural)%>
    <% end %>
    <p><%= submit_tag l(:button_apply), :class => 'button-small' %></p>
    <% end %>
<% end %>