Full calendar have no included options to work-time feature (selecting first and last rows in agenda view for any day - where in example company is not working). I managed something like that:

viewDisplay: function(view){
                    $.ajax({
                        url: 'index.php?r=calendar/Default/worktime',
                        dataType: 'json',
                        success: function(data){
                            if(view.name=='agendaWeek')
                                selectWorkTime(data, 30, 0, 24, false);
                            else if(view.name=='agendaDay')
                                selectDayWorkTime(data, 30, 0, 24, view, false);
                        }
                    });
                }

Where index.php?r=calendar/Default/worktime is php file returning json. It looks like that:

$arr = array(
        'mon' => array('8:00', '17:00'),
        'tue' => array('9:00', '15:00'),
        'wed' => array('9:30', '19:00'),
        'thu' => array('6:00', '14:00'),
        'fri' => array('0:00', '24:00'),
        'sat' => array('9:00', '14:00'),
        'sun' => array()
    );

    foreach ($arr as &$day){
        foreach($day as &$hour){
            $tmp = explode(':', $hour);
            $hour = $tmp[0] * 3600 + $tmp[1] * 60;
        }
    }

    print json_encode($arr);

and at the end, some functions using for counting and selecting work-time:

function selectDayWorkTime(timeArray, slotMinutes, minTime, maxTime, viewObject, showAtHolidays){
    var dayname;
    $('.fc-content').find('.fc-view-agendaWeek').find('.fc-agenda-body')
    .children('.fc-work-time').remove();
    $('.fc-content').find('.fc-view-agendaDay')
    .find('.fc-work-time-day').removeClass('fc-work-time-day');
    switch(viewObject.start.getDay()){
        case 1: dayname='mon'; break;
        case 2: dayname='tue'; break;
        case 3: dayname='wed'; break;
        case 4: dayname='thu'; break;
        case 5: dayname='fri'; break;
        case 6: dayname='sat'; break;
        case 0: dayname='sun'; break;
    }
    for(var day in timeArray){
        if(day == dayname){
            if($('.fc-content').find('.fc-view-agendaDay').find('.fc-'+day).attr('class').search('fc-holiday') == -1 || showAtHolidays){
                var startBefore = 0;
                var endBefore = timeArray[day][0] / (60 * slotMinutes) - (minTime * 60) / slotMinutes;
                var startAfter = timeArray[day][1] / (60 * slotMinutes) - (minTime * 60) / slotMinutes;
                var endAfter = (maxTime - minTime) * 60 / slotMinutes - 1;
                for(startBefore; startBefore < endBefore; startBefore++){
                    $('.fc-view-agendaDay').find('.fc-slot'+startBefore).find('div').addClass('fc-work-time-day');
                }
                for(startAfter; startAfter <= endAfter; startAfter++){
                    $('.fc-view-agendaDay').find('.fc-slot'+startAfter).find('div').addClass('fc-work-time-day');
                }
            }
        }
    }
}

function selectWorkTime(timeArray, slotMinutes, minTime, maxTime, showAtHolidays){
    for(var day in timeArray){
        var startBefore = 0;
        var endBefore = timeArray[day][0] / (60 * slotMinutes) - (minTime * 60) / slotMinutes;
        var startAfter = timeArray[day][1] / (60 * slotMinutes) - (minTime * 60) / slotMinutes;
        var endAfter = (maxTime - minTime) * 60 / slotMinutes - 1;
        if(startBefore > endBefore) endBefore = startBefore;
        if(startAfter > endAfter) startAfter = endAfter;
        try{
            selectCell(startBefore, endBefore, 'fc-'+day, 'fc-work-time', false, showAtHolidays);
            selectCell(startAfter, endAfter, 'fc-'+day, 'fc-work-time', true, showAtHolidays);
        }
        catch(e){
            continue;
        }
    }
}

function selectCell(startRowNo, endRowNo, collClass, cellClass, closeGap, showAtHolidays){
    $('.fc-content').find('.fc-view-agendaWeek').find('.fc-agenda-body')
    .children('.'+cellClass+''+startRowNo+''+collClass).remove();
    $('.fc-content').find('.fc-view-agendaDay')
    .find('.fc-work-time-day').removeClass('fc-work-time-day');
    if($('.fc-content').find('.fc-view-agendaWeek').find('.'+collClass).attr('class').search('fc-holiday') == -1 || showAtHolidays){
        var width = $('.fc-content').find('.fc-view-agendaWeek')
        .find('.'+collClass+':last').width();
        var height = 0;
        if(closeGap && (startRowNo != endRowNo)){
            height = $('.fc-content').find('.fc-view-agendaWeek')
            .find('.fc-slot'+ startRowNo).height();
        }
        $('.fc-view-agendaWeek').find('.fc-agenda-body').prepend('<div class="'+cellClass+' '
            + ''+cellClass+''+startRowNo+''+collClass+'"></div>');
        $('.'+cellClass).width(width - 2);
        height += $('.fc-content').find('.fc-view-agendaWeek')
        .find('.fc-slot'+ endRowNo).position().top
        - $('.fc-content').find('.fc-view-agendaWeek')
        .find('.fc-slot'+ startRowNo).position().top;
        $('.'+cellClass+''+startRowNo+''+collClass).height(height);
        $('.'+cellClass+''+startRowNo+''+collClass)
        .css('margin-top',
            $('.fc-content').find('.fc-view-agendaWeek')
            .find('.fc-slot'+ startRowNo).position().top);
        $('.'+cellClass+''+startRowNo+''+collClass)
        .css('margin-left',
            $('.fc-content').find('.fc-view-agendaWeek')
            .find('.'+collClass+':last').offset().left - width / 2);
    }
}

Don't forget about CSS:

.fc-work-time-day{
        background-color: yellow;
        opacity: 0.3;
        filter: alpha(opacity=30); /* for IE */
    }

    .fc-work-time{
        position: absolute;
        background-color: yellow;
        z-index:10;
        margin: 0;
        padding: 0;
        text-align: left;
        z-index: 0;
        opacity: 0.3;
        filter: alpha(opacity=30); /* for IE */
    }

So, I've got some questions about - is the other way to make the same, but no using absolute div's in agendaWeek? And... How can I get in viewDisplay function actual slotMinutes, minTime and maxTime