Index: api/src/java/org/sakaiproject/signup/logic/SakaiFacade.java
===================================================================
--- api/src/java/org/sakaiproject/signup/logic/SakaiFacade.java	(revision 308214)
+++ api/src/java/org/sakaiproject/signup/logic/SakaiFacade.java	(working copy)
@@ -461,5 +461,6 @@
 	 */
 	public boolean synchonizeGroupTitle(String siteId, String groupId, String newTitle);
 	
-	
+	// Returns Google calendar if the calendar has been created in Google
+	public Calendar getAdditionalCalendar(String siteId) throws PermissionException;
 }
Index: impl/src/java/org/sakaiproject/signup/logic/SakaiFacadeImpl.java
===================================================================
--- impl/src/java/org/sakaiproject/signup/logic/SakaiFacadeImpl.java	(revision 308214)
+++ impl/src/java/org/sakaiproject/signup/logic/SakaiFacadeImpl.java	(working copy)
@@ -44,6 +44,7 @@
 import org.sakaiproject.calendar.api.CalendarEdit;
 import org.sakaiproject.calendar.api.CalendarService;
 import org.sakaiproject.component.api.ServerConfigurationService;
+import org.sakaiproject.component.cover.ComponentManager;
 import org.sakaiproject.content.api.ContentHostingService;
 import org.sakaiproject.exception.IdInvalidException;
 import org.sakaiproject.exception.IdUnusedException;
@@ -207,7 +208,22 @@
 	public void setAuthzGroupService(AuthzGroupService authzGroupService) {
 		this.authzGroupService=authzGroupService;
 	}
-
+	// Returns Google calendar if the calendar has been created in Google
+	public Calendar getAdditionalCalendar(String siteId) throws PermissionException {
+		CalendarService additionalCalendarService = null;
+		additionalCalendarService = (CalendarService) ComponentManager.get(CalendarService.ADDITIONAL_CALENDAR);
+		if (additionalCalendarService != null){
+			if (additionalCalendarService.isCalendarToolInitialized(siteId)) {
+				try {
+					return additionalCalendarService.getCalendar(siteId);
+				} catch (IdUnusedException e) {
+					log.error("Error retrieving Calendar." + e.getMessage());
+				}
+			}
+		}
+		return null;
+	}			
+	
 	/**
 	 * regist all the permission levels, which Signup Tool required. Place any
 	 * code that should run when this class is initialized by spring here
Index: impl/src/java/org/sakaiproject/signup/logic/SignupMeetingServiceImpl.java
===================================================================
--- impl/src/java/org/sakaiproject/signup/logic/SignupMeetingServiceImpl.java	(revision 308214)
+++ impl/src/java/org/sakaiproject/signup/logic/SignupMeetingServiceImpl.java	(working copy)
@@ -648,7 +648,8 @@
 		for (SignupTimeslot calendarBlock : calendarBlocks) {			
 			for (SignupSite site : signupSites) {
 				try {
-					Calendar calendar = sakaiFacade.getCalendar(site.getSiteId());
+					Calendar calendar = chooseCalendar(site);
+					
 					if (calendar == null)// something went wrong when fetching the calendar
 						continue;
 	
@@ -916,7 +917,8 @@
 
 			for (SignupSite site : sites) {
 				try {
-					Calendar calendar = sakaiFacade.getCalendar(site.getSiteId());
+					Calendar calendar = chooseCalendar(site);
+
 					if (calendar == null)// something went wrong when fetching the calendar
 						continue;
 
@@ -960,6 +962,16 @@
 		}
 
 	}
+
+	// See if additional calendar is deployed and ready to use.
+	// If not, we use the Sakai calendar tool by default.
+	private Calendar chooseCalendar(SignupSite site) throws PermissionException {
+		Calendar calendar = sakaiFacade.getAdditionalCalendar(site.getSiteId());
+		if (calendar == null) {
+			calendar = sakaiFacade.getCalendar(site.getSiteId());
+		}
+		return calendar;
+	}
 	
 	/**
 	 * {@inheritDoc}