diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 7c9cffae..1c5801a1 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -52,6 +52,8 @@ class calendar extends rcube_plugin
     'calendar_timeslots'    => 2,
     'calendar_first_day'    => 1,
     'calendar_first_hour'   => 6,
+    'calendar_work_start'   => 6,
+    'calendar_work_end'     => 18,
   );
 
   private $default_categories = array(
@@ -627,6 +629,8 @@ class calendar extends rcube_plugin
     $settings['timeslots'] = (int)$this->rc->config->get('calendar_timeslots', $this->defaults['calendar_timeslots']);
     $settings['first_day'] = (int)$this->rc->config->get('calendar_first_day', $this->defaults['calendar_first_day']);
     $settings['first_hour'] = (int)$this->rc->config->get('calendar_first_hour', $this->defaults['calendar_first_hour']);
+    $settings['work_start'] = (int)$this->rc->config->get('calendar_work_start', $this->defaults['calendar_work_start']);
+    $settings['work_end'] = (int)$this->rc->config->get('calendar_work_end', $this->defaults['calendar_work_end']);
     $settings['timezone'] = $this->timezone;
 
     // localization
diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index ed0318e4..bfa2614d 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -42,9 +42,10 @@ function rcube_calendar_ui(settings)
     var gmt_offset = (new Date().getTimezoneOffset() / -60) - (settings.timezone || 0);
     var day_clicked = day_clicked_ts = 0;
     var ignore_click = false;
+    var event_defaults = { free_busy:'busy' };
     var event_attendees = null;
     var attendees_list;
-    var freebusy_ui = {};
+    var freebusy_ui = { workinhoursonly:false };
     var freebusy_data = {};
     var freebusy_needsupdate;
 
@@ -330,7 +331,8 @@ function rcube_calendar_ui(settings)
       
       var $dialog = $("#eventedit");
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:action=='new' };
-      me.selected_event = $.extend({}, event);  // clone event object
+      me.selected_event = $.extend(event_defaults, event);  // clone event object (with defaults)
+      event = me.selected_event; // change reference to clone
       freebusy_needsupdate = false;
 
       // reset dialog first, enable/disable fields according to editable state
@@ -616,27 +618,34 @@ function rcube_calendar_ui(settings)
         return false;
       
       // set form elements
-      var duration = Math.round((event.end.getTime() - event.start.getTime()) / 1000);
-      var startdate = $('#schedule-startdate').val($.fullCalendar.formatDate(event.start, settings['date_format'])).data('duration', duration);
-      var starttime = $('#schedule-starttime').val($.fullCalendar.formatDate(event.start, settings['time_format'])).show();
-      var enddate = $('#schedule-enddate').val($.fullCalendar.formatDate(event.end, settings['date_format']));
-      var endtime = $('#schedule-endtime').val($.fullCalendar.formatDate(event.end, settings['time_format'])).show();
       var allday = $('#edit-allday').get(0);
+      var duration = Math.round((event.end.getTime() - event.start.getTime()) / 1000);
+      freebusy_ui.startdate = $('#schedule-startdate').val($.fullCalendar.formatDate(event.start, settings['date_format'])).data('duration', duration);
+      freebusy_ui.starttime = $('#schedule-starttime').val($.fullCalendar.formatDate(event.start, settings['time_format'])).show();
+      freebusy_ui.enddate = $('#schedule-enddate').val($.fullCalendar.formatDate(event.end, settings['date_format']));
+      freebusy_ui.endtime = $('#schedule-endtime').val($.fullCalendar.formatDate(event.end, settings['time_format'])).show();
       
       if (allday.checked) {
         starttime.val("00:00").hide();
         endtime.val("23:59").hide();
+        event.allDay = true;
       }
       
+      // read attendee roles from drop-downs
+      $('select.edit-attendee-role').each(function(i, elem){
+        if (event_attendees[i])
+          event_attendees[i].role = $(elem).val();
+      });
+      
       // render time slots
       var now = new Date(), fb_start = new Date(), fb_end = new Date();
-      fb_start.setTime(Math.max(now, event.start));
+      fb_start.setTime(event.start);
       fb_start.setHours(0); fb_start.setMinutes(0); fb_start.setSeconds(0); fb_start.setMilliseconds(0);
       fb_end.setTime(fb_start.getTime() + 86400000);
       
       freebusy_data = {};
       freebusy_ui.loading = 1;  // prevent render_freebusy_grid() to load data yet
-      freebusy_ui.numdays = allday.checked ? 7 : 1;
+      freebusy_ui.numdays = allday.checked ? 7 : Math.ceil(duration * 2 / 86400);
       freebusy_ui.interval = allday.checked ? 360 : 60;
       freebusy_ui.start = fb_start;
       freebusy_ui.end = new Date(freebusy_ui.start.getTime() + 86400000 * freebusy_ui.numdays);
@@ -653,9 +662,23 @@ function rcube_calendar_ui(settings)
       
       $('#schedule-attendees-list').html(list_html);
       
+      // enable/disable buttons
+      $('#shedule-find-prev').button('option', 'disabled', (fb_start.getTime() < now.getTime()));
+      
       // dialog buttons
       var buttons = {};
       
+      buttons[rcmail.gettext('adobt', 'calendar')] = function() {
+        $('#edit-startdate').val(freebusy_ui.startdate.val());
+        $('#edit-starttime').val(freebusy_ui.starttime.val());
+        $('#edit-enddate').val(freebusy_ui.enddate.val());
+        $('#edit-endtime').val(freebusy_ui.endtime.val());
+        if (freebusy_needsupdate)
+          update_freebusy_status(me.selected_event);
+        freebusy_needsupdate = false;
+        $dialog.dialog("close");
+      };
+      
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
@@ -666,6 +689,8 @@ function rcube_calendar_ui(settings)
         closeOnEscape: true,
         title: rcmail.gettext('scheduletime', 'calendar'),
         close: function() {
+          if (bw.ie6)
+            $("#edit-attendees-table").css('visibility','visible');
           $dialog.dialog("destroy").hide();
         },
         buttons: buttons,
@@ -673,6 +698,10 @@ function rcube_calendar_ui(settings)
         width: 850
       }).show();
       
+      // hide edit dialog on IE6 because of drop-down elements
+      if (bw.ie6)
+        $("#edit-attendees-table").css('visibility','hidden');
+      
       // adjust dialog size to fit grid without scrolling
       var gridw = $('#schedule-freebusy-times').width();
       var overflow = gridw - $('#attendees-freebusy-table td.times').width() + 1;
@@ -704,8 +733,8 @@ function rcube_calendar_ui(settings)
           lastdate = datestr;
         }
         
-        // TODO: define working hours by config
-        css = (freebusy_ui.numdays == 1 && (curdate.getHours() < 6 || curdate.getHours() > 18)) ? 'offhours' : 'workinghours';
+        // set css class according to working hours
+        css = (freebusy_ui.numdays == 1 && (curdate.getHours() < settings['work_start'] || curdate.getHours() > settings['work_end'])) ? 'offhours' : 'workinghours';
         times_row += '<td class="' + css + '">' + Q($.fullCalendar.formatDate(curdate, settings['time_format'])) + '</td>';
         slots_row += '<td class="' + css + ' unknown">&nbsp;</td>';
         
@@ -749,15 +778,15 @@ function rcube_calendar_ui(settings)
     {
       var overlay = $('#schedule-event-time');
       if (me.selected_event.end.getTime() < freebusy_ui.start.getTime() || me.selected_event.start.getTime() > freebusy_ui.end.getTime()) {
-        overlay.hide();
+        overlay.draggable('disable').hide();
       }
       else {
         var table = $('#schedule-freebusy-times'),
           width = 0,
           pos = { top:table.children('thead').height(), left:0 },
-          eventstart = Math.floor(me.selected_event.start.getTime() / 1000),
-          eventend = Math.floor(me.selected_event.end.getTime() / 1000),
-          slotstart = Math.floor(freebusy_ui.start.getTime() / 1000),
+          eventstart = date2unixtime(me.selected_event.start),
+          eventend = date2unixtime(me.selected_event.end),
+          slotstart = date2unixtime(freebusy_ui.start),
           slotsize = freebusy_ui.interval * 60,
           slotend, fraction, $cell;
         
@@ -782,14 +811,38 @@ function rcube_calendar_ui(settings)
           width = table.width() - pos.left;
 
         // overlay is visible
-        if (width > 0)
-          overlay.css({ width: (width-5)+'px', height:(table.children('tbody').height() - 4)+'px', left:pos.left+'px', top:pos.top+'px' }).show();
+        if (width > 0) {
+          overlay.css({ width: (width-5)+'px', height:(table.children('tbody').height() - 4)+'px', left:pos.left+'px', top:pos.top+'px' }).draggable('enable').show();
+          
+          // configure draggable
+          if (!overlay.data('isdraggable')) {
+            overlay.draggable({
+              axis: 'x',
+              scroll: true,
+              stop: function(e, ui){
+                // convert pixels to time
+                var px = ui.position.left;
+                var range_p = $('#schedule-freebusy-times').width();
+                var range_t = freebusy_ui.end.getTime() - freebusy_ui.start.getTime();
+                var newstart = new Date(freebusy_ui.start.getTime() + px * (range_t / range_p));
+                newstart.setSeconds(0); newstart.setMilliseconds(0);
+                // round to 5 minutes
+                var round = newstart.getMinutes() % 5;
+                if (round > 2.5) newstart.setTime(newstart.getTime() + (5 - round) * 60000);
+                else if (round > 0) newstart.setTime(newstart.getTime() - round * 60000);
+                // update event times
+                update_freebusy_dates(newstart, new Date(newstart.getTime() + freebusy_ui.startdate.data('duration') * 1000));
+              }
+            }).data('isdraggable', true);
+          }
+        }
         else
-          overlay.hide();
+          overlay.draggable('disable').hide();
       }
       
     };
     
+    
     // fetch free-busy information for each attendee from server
     var load_freebusy_data = function(from, interval)
     {
@@ -851,6 +904,109 @@ function rcube_calendar_ui(settings)
         });
       }
     };
+    
+    // write changed event date/times back to form fields
+    var update_freebusy_dates = function(start, end)
+    {
+      me.selected_event.start = start;
+      me.selected_event.end = end;
+      freebusy_ui.startdate.val($.fullCalendar.formatDate(start, settings['date_format']));
+      freebusy_ui.starttime.val($.fullCalendar.formatDate(start, settings['time_format']));
+      freebusy_ui.enddate.val($.fullCalendar.formatDate(end, settings['date_format']));
+      freebusy_ui.endtime.val($.fullCalendar.formatDate(end, settings['time_format']));
+      freebusy_needsupdate = true;
+    };
+
+    // attempt to find a time slot where all attemdees are available
+    var freebusy_find_slot = function(dir)
+    {
+      var event = me.selected_event,
+        eventstart = date2unixtime(event.start),  // calculate with unitimes
+        eventend = date2unixtime(event.end),
+        duration = eventend - eventstart,
+        sinterval = freebusy_data.interval * 60,
+        intvlslots = event.allDay ? 4 : 1,
+        numslots = Math.ceil(duration / sinterval),
+        checkdate, slotend, email, curdate;
+
+      // shift event times to next possible slot
+      eventstart += sinterval * intvlslots * dir;
+      eventend += sinterval * intvlslots * dir;
+
+      // iterate through free-busy slots and find candidates
+      var candidatecount = 0, candidatestart = candidateend = success = false;
+      for (var slot = dir > 0 ? freebusy_data.start : freebusy_data.end - sinterval; (dir > 0 && slot < freebusy_data.end) || (dir < 0 && slot >= freebusy_data.start); slot += sinterval * dir) {
+        slotend = slot + sinterval;
+        if ((dir > 0 && slotend <= eventstart) || (dir < 0 && slot >= eventend))  // skip
+          continue;
+        
+        // respect workingours setting
+        if (freebusy_ui.workinhoursonly && freebusy_data.interval <= 60) {
+          curdate = fromunixtime(dir > 0 || !candidateend ? slot : (candidateend - duration));
+          if (curdate.getHours() < settings['work_start'] || curdate.getHours() > settings['work_end']) {  // skip off-hours
+            candidatestart = candidateend = false;
+            candidatecount = 0;
+            continue;
+          }
+        }
+        
+        if (!candidatestart)
+          candidatestart = slot;
+        
+        // check freebusy data for all attendees
+        for (var i=0; i < event_attendees.length; i++) {
+          if ((email = event_attendees[i].email) && freebusy_data[email][slot] > 1) {
+            candidatestart = candidateend = false;
+            break;
+          }
+        }
+        
+        // occupied slot
+        if (!candidatestart) {
+          slot += Math.max(0, intvlslots - candidatecount - 1) * sinterval * dir;
+          candidatecount = 0;
+          continue;
+        }
+        
+        // set candidate end to slot end time
+        candidatecount++;
+        if (dir < 0 && !candidateend)
+          candidateend = slotend;
+        
+        // if candidate is big enough, this is it!
+        if (candidatecount == numslots) {
+          if (dir > 0) {
+            event.start = fromunixtime(candidatestart);
+            event.end = fromunixtime(candidatestart + duration);
+          }
+          else {
+            event.end = fromunixtime(candidateend);
+            event.start = fromunixtime(candidateend - duration);
+          }
+          success = true;
+          break;
+        }
+      }
+      
+      // update event date/time display
+      if (success) {
+        update_freebusy_dates(event.start, event.end);
+        
+        // move freebusy grid if necessary
+        if (event.start.getTime() >= freebusy_ui.end.getTime())
+          render_freebusy_grid(1);
+        else if (event.end.getTime() <= freebusy_ui.start.getTime())
+          render_freebusy_grid(-1);
+        else
+          render_freebusy_overlay();
+        
+        var now = new Date();
+        $('#shedule-find-prev').button('option', 'disabled', (event.start.getTime() < now.getTime()));
+      }
+      else {
+        alert(rcmail.gettext('noslotfound','calendar'));
+      }
+    };
 
 
     // update event properties and attendees availability if event times have changed
@@ -858,6 +1014,7 @@ function rcube_calendar_ui(settings)
     {
       if (me.selected_event) {
         var allday = $('#edit-allday').get(0);
+        me.selected_event.allDay = allday.checked;
         me.selected_event.start = parse_datetime(allday.checked ? '00:00' : $('#edit-starttime').val(), $('#edit-startdate').val());
         me.selected_event.end   = parse_datetime(allday.checked ? '23:59' : $('#edit-endtime').val(), $('#edit-enddate').val());
         if (event_attendees)
@@ -1701,7 +1858,11 @@ function rcube_calendar_ui(settings)
     $('#shedule-freebusy-prev').html(bw.ie6 ? '&lt;&lt;' : '&#9668;').button().click(function(){ render_freebusy_grid(-1); });
     $('#shedule-freebusy-next').html(bw.ie6 ? '&gt;&gt;' : '&#9658;').button().click(function(){ render_freebusy_grid(1); }).parent().buttonset();
     
+    $('#shedule-find-prev').button().click(function(){ freebusy_find_slot(-1); });
+    $('#shedule-find-next').button().click(function(){ freebusy_find_slot(1); });
+    
     $('#schedule-freebusy-wokinghours').click(function(){
+      freebusy_ui.workinhoursonly = this.checked;
       $('#workinghourscss').remove();
       if (this.checked)
         $('<style type="text/css" id="workinghourscss"> td.offhours { opacity:0.3; filter:alpha(opacity=30) } </style>').appendTo('head');
diff --git a/plugins/calendar/config.inc.php.dist b/plugins/calendar/config.inc.php.dist
index aa580071..a6b23415 100644
--- a/plugins/calendar/config.inc.php.dist
+++ b/plugins/calendar/config.inc.php.dist
@@ -52,6 +52,12 @@ $rcmail_config['calendar_first_day'] = 1;
 // first hour of the calendar (0-23)
 $rcmail_config['calendar_first_hour'] = 6;
 
+// working hours begin
+$rcmail_config['calendar_work_start'] = 6;
+
+// working hours end
+$rcmail_config['calendar_work_end'] = 18;
+
 // event categories
 $rcmail_config['calendar_categories'] = array(
   'Personal' => 'c0c0c0',
diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index 74e1228c..07eb7b0a 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -591,7 +591,7 @@ class calendar_ui
     $table->add('attendees',
       html::tag('h3', 'boxtitle', $this->calendar->gettext('tabattendees')) .
       html::div('timesheader', '&nbsp;') .
-      html::div(array('id' => 'schedule-attendees-list'), '')
+      html::div(array('id' => 'schedule-attendees-list', 'class' => 'attendees-list'), '')
     );
     $table->add('times',
       html::div('scroll',
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index ab4bf5c4..4b405ee5 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -31,6 +31,7 @@ $labels['edit'] = 'Edit';
 $labels['save'] = 'Save';
 $labels['remove'] = 'Remove';
 $labels['cancel'] = 'Cancel';
+$labels['adobt'] = 'Adopt changes';
 $labels['print'] = 'Print calendars';
 $labels['title'] = 'Summary';
 $labels['description'] = 'Description';
@@ -99,7 +100,10 @@ $labels['availtentative'] = 'Tentative';
 $labels['availoutofoffice'] = 'Out of Office';
 $labels['scheduletime'] = 'Available times';
 $labels['sendnotifications'] = 'Send notifications';
-$labels['onlyworkinghours'] = 'Show only working hours';
+$labels['onlyworkinghours'] = 'Only working hours';
+$labels['prevslot'] = 'Previous Slot';
+$labels['nextslot'] = 'Next Slot';
+$labels['noslotfound'] = 'Unable to find a free time slot';
 
 // event dialog tabs
 $labels['tabsummary'] = 'Summary';
diff --git a/plugins/calendar/skins/default/calendar.css b/plugins/calendar/skins/default/calendar.css
index aeb8a9ec..64669a92 100644
--- a/plugins/calendar/skins/default/calendar.css
+++ b/plugins/calendar/skins/default/calendar.css
@@ -597,6 +597,7 @@ td.topalign {
 
 #edit-attendees-legend {
 	margin-top: 3em;
+	margin-bottom: 0.5em;
 }
 
 #edit-attendees-legend .legend {
@@ -667,13 +668,33 @@ td.topalign {
 	border-color: #ccc;
 }
 
-#schedule-attendees-list div.attendee {
-	padding: 3px 20px 3px 6px;
+.attendees-list .attendee {
+	padding: 3px 4px 3px 20px;
+	background: url('images/attendee-status.gif') 2px -97px no-repeat;
+}
+
+.attendees-list div.attendee {
 	border-top: 1px solid #ccc;
 }
 
-#schedule-attendees-list div.loading {
-	background: url('images/loading-small.gif') top right no-repeat;
+.attendees-list span.attendee {
+	margin-right: 2em;
+}
+
+.attendees-list .organizer {
+	background-position: 3px -77px;
+}
+
+.attendees-list .opt-participant {
+	background-position: 2px -117px;
+}
+
+.attendees-list .chair {
+	background-position: 2px -137px;
+}
+
+.attendees-list .loading {
+	background: url('images/loading-small.gif') 1px 50% no-repeat;
 }
 
 #schedule-freebusy-times {
@@ -706,11 +727,12 @@ td.topalign {
 	background: rgba(60, 60, 60, 0.6);
 	opacity: 0.5;
 	border-radius: 4px;
+	cursor: move;
 }
 
 #eventfreebusy .schedule-options {
 	position: relative;
-	margin-bottom: 2em;
+	margin-bottom: 1.5em;
 }
 
 #eventfreebusy .schedule-buttons {
@@ -719,6 +741,15 @@ td.topalign {
 	right: 0;
 }
 
+#eventfreebusy .schedule-find-buttons {
+	padding-bottom:0.5em;
+}
+
+#eventfreebusy .schedule-find-buttons button {
+	min-width: 9em;
+	text-align: center;
+}
+
 span.edit-alarm-set {
 	white-space: nowrap;
 }
diff --git a/plugins/calendar/skins/default/images/attendee-status.gif b/plugins/calendar/skins/default/images/attendee-status.gif
index a5f65a02..5c08aae3 100644
Binary files a/plugins/calendar/skins/default/images/attendee-status.gif and b/plugins/calendar/skins/default/images/attendee-status.gif differ
diff --git a/plugins/calendar/skins/default/templates/calendar.html b/plugins/calendar/skins/default/templates/calendar.html
index bf83f030..de0419cc 100644
--- a/plugins/calendar/skins/default/templates/calendar.html
+++ b/plugins/calendar/skins/default/templates/calendar.html
@@ -188,25 +188,42 @@
   <roundcube:object name="plugin.attendees_freebusy_table" id="attendees-freebusy-table" cellspacing="0" cellpadding="0" border="0" />
   
   <div class="schedule-options">
-    <label><input type="checkbox" id="schedule-freebusy-wokinghours" value="1" /><roundcube:label name="calendar.onlyworkinghours" /></label>
+    &nbsp;
     <div class="schedule-buttons">
-      <button id="shedule-freebusy-prev" title="<roundcube:label name='previouspage' />">&#9668;</button>
-      <button id="shedule-freebusy-next" title="<roundcube:label name='nextpage' />">&#9658;</button>
+      <button id="shedule-freebusy-prev" title="<roundcube:label name='previouspage' />">&#9668;</button><button id="shedule-freebusy-next" title="<roundcube:label name='nextpage' />">&#9658;</button>
     </div>
   </div>
   
-  <div class="form-section">
-    <label for="schedule-startdate"><roundcube:label name="calendar.start" /></label>
-    <input type="text" name="startdate" size="10" id="schedule-startdate" disabled="true" /> &nbsp;
-    <input type="text" name="starttime" size="6" id="schedule-starttime" disabled="true" />
+  <div style="float:left; width:28em">
+    <div class="form-section">
+      <label for="schedule-startdate"><roundcube:label name="calendar.start" /></label>
+      <input type="text" name="startdate" size="10" id="schedule-startdate" disabled="true" /> &nbsp;
+      <input type="text" name="starttime" size="6" id="schedule-starttime" disabled="true" />
+    </div>
+    <div class="form-section">
+      <label for="schedule-enddate"><roundcube:label name="calendar.end" /></label>
+      <input type="text" name="enddate" size="10" id="schedule-enddate" disabled="true" /> &nbsp;
+      <input type="text" name="endtime" size="6"  id="schedule-endtime" disabled="true" />
+    </div>
   </div>
-  <div class="form-section">
-    <label for="schedule-enddate"><roundcube:label name="calendar.end" /></label>
-    <input type="text" name="enddate" size="10" id="schedule-enddate" disabled="true" /> &nbsp;
-    <input type="text" name="endtime" size="6"  id="schedule-endtime" disabled="true" />
+  <div style="float:left">
+    <div class="schedule-find-buttons">
+      <button id="shedule-find-prev">&#9668; <roundcube:label name="calendar.prevslot" /></button>
+      <button id="shedule-find-next"><roundcube:label name="calendar.nextslot" /> &#9658;</button>
+    </div>
+    <div class="schedule-options">
+      <label><input type="checkbox" id="schedule-freebusy-wokinghours" value="1" /><roundcube:label name="calendar.onlyworkinghours" /></label>
+    </div>
   </div>
+  <br style="clear:both;" />
   
   <roundcube:include file="/templates/freebusylegend.html" />
+  <div class="attendees-list">
+    <span class="attendee organizer"><roundcube:label name="calendar.roleorganizer" /></span>
+    <span class="attendee req-participant"><roundcube:label name="calendar.rolerequired" /></span>
+    <span class="attendee opt-participant"><roundcube:label name="calendar.roleoptional" /></span>
+    <span class="attendee chair"><roundcube:label name="calendar.roleresource" /></span>
+  </div>
 </div>
 
 <div id="calendarform" class="uidialog">