1. Full Page calendar
2. Component

<apex:page controller="repeatCon" id="thePage"
    showHeader="false">
    <apex:form id="theForm">
        <apex:outputPanel id="theCalendar">
            <div class="bCalendar">
            <table class="calendarMonthView" width="100%">
                <caption>
                <div class="calHeader"><apex:commandLink action="{!prev}"
                    rerender="theCalendar">
                    <img title="Previous Month" class="prevCalArrow"
                        alt="Previous Month" src="/s.gif" />
                </apex:commandLink>
                &nbsp;&nbsp;{!month.monthname}&nbsp;&nbsp;{!month.yearname}&nbsp;&nbsp;
                <apex:commandLink action="{!next}" rerender="theCalendar">
                    <img title="Next Month" class="nextCalArrow" alt="Next Month"
                        src="/s.gif" />
                </apex:commandLink></div>
                </caption>
                <tbody>
                    <tr class="headerRow">
                        <th scope="col" class="calDays">Sunday</th>
                        <th scope="col" class="calDays">Monday</th>
                        <th scope="col" class="calDays">Tuesday</th>
                        <th scope="col" class="calDays">Wednesday</th>
                        <th scope="col" class="calDays">Thursday</th>
                        <th scope="col" class="calDays">Friday</th>
                        <th scope="col" class="calDays">Saturday</th>
                    </tr>

                    <apex:repeat value="{!weeks}" var="wk" id="foreachWeek">
                        <tr>
                            <apex:repeat value="{!wk.days}" var="day" id="foreachday">
                                <td class="{!day.cssname}" height="90" valign="top">
                                <div class="date"><a href="#"
                                    title="Add Event - {!day.date}"><img src="/s.gif"
                                    alt="Add Event - {!day.date}" class="addNewEventIcon"
                                    title="Add Event - {!day.date}" /></a> <a href="#"
                                    title="Day View - {!day.date}">{!day.dayofmonth}</a></div>

                                <div><apex:repeat value="{!day.eventstoday}" var="v"
                                    id="foreachevent">
                                    <span class="event">{!v.formateddate}</span>
                                    <a href="#">{!v.ev.subject}</a>
                                    <br />
                                </apex:repeat></div>
                                </td>
                            </apex:repeat>
                        </tr>

                    </apex:repeat>

                </tbody>
            </table>
            </div>
        </apex:outputPanel>

    </apex:form>
</apex:page>

public class eventItem {
    public Event ev;
    public String formatedDate; 
    public eventItem(Event e) { 
        ev= e;
        // build formated date
        //9:00 AM - 1:00 PM
    //  system.debug(e.activitydatetime.format('MMM a'));
    //  system.debug(e.DurationInMinutes);
        Datetime endd = e.activitydatetime.addMinutes(e.DurationInMinutes);
        //system.debug(e.activitydatetime.format('h:mm a '));
        formatedDate = e.activitydatetime.format('h:mm a') + 
        ' - ' + endd.format('h:mm a');
        system.debug(formateddate);
    }
    public Event getEv() { return ev; }
    public String getFormatedDate() { return formatedDate; }
}

public class Month {
    private List<Week> weeks; 
    public Date firstDate; // always the first of the month
    private Date upperLeft; 
    
    public List<Date> getValidDateRange() { 
        // return one date from the upper left, and one from the lower right
        List<Date> ret = new List<Date>();
        ret.add(upperLeft);
        ret.add(upperLeft.addDays(5*7) );
        return ret;
    }
    
    public String getMonthName() { 
        return DateTime.newInstance(firstDate.year(),firstdate.month(),firstdate.day()).format('MMMM');
    } 
    
    public String getYearName() { 
        return DateTime.newInstance(
        firstDate.year(),firstdate.month(),firstdate.day()).format('yyyy');
    } 
    
    public String[] getWeekdayNames() { 
        Date today = system.today().toStartOfWeek();
        DateTime dt = DateTime.newInstanceGmt(today.year(),today.month(),today.day());      
        list<String> ret = new list<String>();
        for(Integer i = 0; i < 7;i++) { 
            ret.add( dt.formatgmt('EEEE') );
            dt= dt.addDays(1);
        } 
        return ret;
    }
    
    public Date getfirstDate() { return firstDate; } 

    public Month( Date value ) {
        weeks = new List<Week>();
        firstDate = value.toStartOfMonth();
        upperLeft = firstDate.toStartOfWeek();
        Date tmp = upperLeft;
        for (Integer i = 0; i < 5; i++) {
            Week w = new Week(i+1,tmp,value.month());   
            system.assert(w!=null); 
            this.weeks.add( w );
            tmp = tmp.addDays(7);
        }

    }
 
    public void setEvents(List<Event> ev) { 
        // merge these events into the proper day 
        for(Event e:ev) { 
            for(Week w:weeks) { 
                for(Day c: w.getDays() ) { 
                    if ( e.ActivityDate.isSameDay(c.theDate))  { 
                        // add this event to this calendar date
                        c.eventsToday.add(new EventItem(e));
                        // add only three events, then a More... label if there are more
                    } 
                } 
            } 
        }
    }
    
    public List<Week> getWeeks() { 
        system.assert(weeks!=null,'could not create weeks list');
        return this.weeks; 
    }
        

    /* 
     * helper classes to define a month in terms of week and day
     */
    public class Week {
     public List<Day> days;
     public Integer weekNumber; 
     public Date startingDate; // the date that the first of this week is on
     // so sunday of this week
     
     public List<Day> getDays() { return this.days; }
     
     public Week () { 
        days = new List<Day>();     
     }
     public Week(Integer value,Date sunday,Integer month) { 
        this();
        weekNumber = value;
        startingDate = sunday;
        Date tmp = startingDate;
        for (Integer i = 0; i < 7; i++) {
            Day d = new Day( tmp,month ); 
            tmp = tmp.addDays(1);
            d.dayOfWeek = i+1;          
        //  system.debug(d);
            days.add(d);
        } 
        
     }
     public Integer getWeekNumber() { return this.weekNumber;}
     public Date getStartingDate() { return this.startingDate;}
     
    }
    
    public class Day {
         
        public Date         theDate;
        public List<EventItem>  eventsToday; // list of events for this date
        public Integer      month, dayOfWeek;
        public String       formatedDate; // for the formated time  
        private String      cssclass = 'calActive';
         
        public Date         getDate() { return theDate; }
        public Integer      getDayOfMonth() { return theDate.day(); }
        public String       getDayOfMonth2() { 
            if ( theDate.day() <= 9 ) 
                return '0'+theDate.day(); 
            return String.valueof( theDate.day()); 
        }
        public Integer getDayOfYear() { return theDate.dayOfYear(); }
        public List<EventItem>  getDayAgenda() { return eventsToday; }
        public String       getFormatedDate() { return formatedDate; }
        public Integer      getDayNumber() { return dayOfWeek; }
        public List<EventItem>  getEventsToday() { return eventsToday; }
        public String       getCSSName() {  return cssclass; }
        
        public Day(Date value,Integer vmonth) { 
            theDate=value; month=vmonth;        
            formatedDate = '12 21 08';// time range..
            //9:00 AM - 1:00 PM
            eventsToday = new List<EventItem>();  
            // three possible Inactive,Today,Active  
            if ( theDate.daysBetween(System.today()) == 0 ) cssclass ='calToday';
            // define inactive, is the date in the month?
            if ( theDate.month() != month) cssclass = 'calInactive';
        }
            
    }

/*  static testMethod void testMe() {
        Month m = new Month( Date.newInstance(2007,11,1) );
        system.assert(m!=null); 
        List<Week> l = m.getWeeks(); 
        repeatcon r = new repeatcon(); 
        system.debug(m.getMonthName());
        Month mm = r.getMonth();
        //system.debug(mm); 
        system.debug(m.getFirstDate());
        system.debug(m.getWeekdayNames());
        for(Week w:r.getWeeks()) { 
            for(Day c:w.days) {   
                if (c.eventsToday.size() > 0 ) { 
                    String ss = String.valueOf(c.eventsToday[0].ev.ActivityDate);
                    ss = c.eventsToday[0].ev.ActivityDateTime.format('MMMM a');
                    //system.debug(ss);
                    //system.debug(c.eventsToday[0].ev);
                } 
            } 
        } 
    }*/
}

public class repeatCon {

  public void next() { 
    addMonth(1);
  }

  public void prev() { 
    addMonth(-1); 
  }

  public repeatCon() {
 
   Date d = system.today();  // default to today 
   Integer mo = d.month(); 
   String m_param = System.currentPageReference().getParameters().get('mo');
   String y_param = System.currentPageReference().getParameters().get('yr');
   
   // allow a month to be passed in on the url as mo=10
   if (m_param != null) { 
        Integer mi = Integer.valueOf(m_param); 
        if (mi > 0 && mi <= 12) {
          d = Date.newInstance(d.year(),mi,d.day());
        }
   }
   // and year as yr=2008
   if (y_param != null) { 
        Integer yr = Integer.valueOf(y_param); 
        d = Date.newInstance(yr, d.month(), d.day());
   }

   setMonth(d);
  }
 
  public List<Month.Week> getWeeks() { 
    system.assert(month!=null,'month is null');
    return month.getWeeks();
  }
  
  public Month getMonth() { return month; } 


  private void setMonth(Date d) { 
    month = new Month(d);  
    system.assert(month != null); 

    Date[] da = month.getValidDateRange();  // gather events that fall in this month
    events = [ select id,subject,description,activitydate,activitydatetime,DurationInMinutes
        from Event 
        where activitydate >= :da[0] AND activityDate <= :da[1]
        order by activitydatetime];

    month.setEvents(events);  // merge those events into the month class
  }
  
  private void addMonth(Integer val) { 
    Date d = month.getFirstDate();
    d = d.addMonths(val);
    setMonth(d);
  }

  private List<Event> events;
  private Month month;
}

<apex:component controller="repeatCon" >
    <apex:stylesheet value="/sCSS/Theme2/default/homeCalendar.css" />
    
    <apex:form id="theForm">
         <apex:outputPanel id="theCalendar" >
         
            <div class="mCalendar" style="width:182px;" ><div class="topLeft" ><div class="topRight"/></div>
            <div class="body">
            <table cellspacing="0" cellpadding="2" border="0">
                <tbody>
                    <tr class="header">
                        <td><apex:commandLink action="{!prev}" rerender="theCalendar">
                            <img title="Previous Month" class="prevCalArrow"
                                alt="Previous Month" src="/s.gif" />
                        </apex:commandLink></td>
                        <td colspan="5" >{!month.monthname} {!month.yearname}
                        </td>
                        <td><apex:commandLink action="{!next}" rerender="theCalendar">
                            <img title="Next Month" class="nextCalArrow" alt="Next Month"
                                src="/s.gif" />
                        </apex:commandLink></td>
                    </tr>
                    <tr>
                        <th scope="col" class="calDays">Sun</th>
                        <th scope="col" class="calDays">Mon</th>
                        <th scope="col" class="calDays">Tue</th>
                        <th scope="col" class="calDays">Wed</th>
                        <th scope="col" class="calDays">Thu</th>
                        <th scope="col" class="calDays">Fri</th>
                        <th scope="col" class="calDays">Sat</th>
                    </tr>
                    <apex:repeat value="{!weeks}" var="wk" id="foreachWeek">
                        <tr class="days">
                            <!-- or highlight -->
                            <apex:repeat value="{!wk.days}" var="day" id="foreachday">
                                <td valign="top"><a class="calActive"
                                    href="/00U/c?md0=2008&md3={!day.dayOfYear}" target="_blank"
                                    title="Day View - {!day.date}">{!day.dayofmonth2}</a></td>
                            </apex:repeat>
                        </tr>
                    </apex:repeat>
                </tbody>
            </table>
            </div>
            <div class="bottomLeft"><div class="bottomRight"/></div>
            </div>
            
            </apex:outputPanel>
        </apex:form>

</apex:component>