Table based calendar only using Twig

calendar.twig

{#
 time can be any string acceptable by http://www.php.net/strtotime, the
 template will output that time's month.

 If you don't want to pass in a date you can set time like this:
 {% set time = "now"|date("U") %}
 {% set time = "December 2012"|date("U") %}
 
 Data (in activityByDay) is collated by activityByDay[year][month][day], which holds a list
 of activity data for each day. YMMV for your own needs.
#}

    {% for year,months in activityByDay %}
        {% for month, days in months %}
            {% set execution = days|first|first %}
            {% set time = execution.actionStamp|date("U") %}
            <table class="table table-bordered">
                <thead>
                <tr class="month-name">
                    <th colspan="7" class="text-center">{{ time|date('F Y') }}</th>
                </tr>
                <tr class="week-name">
                    <th>Sunday</th>
                    <th>Monday</th>
                    <th>Tuesday</th>
                    <th>Wednesday</th>
                    <th>Thursday</th>
                    <th>Friday</th>
                    <th>Saturday</th>
                </tr>
                </thead>
                <tbody>
                <tr>
                    {% set daysInMonth = time|date('t') %}
                    {% set startDow = time|date('F 1\\s\\t Y')|date('w') %}
                    {% set dow = startDow %}
                    {% for day in range(1,daysInMonth) %}
                        {% if loop.first and startDow != 0 %}
                        <td colspan="{{ startDow }}"></td>
                        {% endif %}
                        <td>
                            <div>
                                <div>{{ day }}</div>
                                <div class="day">
                                    {% if days[day] is defined %}
                                        {% for activity in days[day] %}
                                            <a href="{{ path('activity_page', {'activityId':activity.id}) }}">{{ activity.name }}</a><br>
                                        {% endfor %}
                                    {% endif %}
                                </div>
                            </div>
                        </td>
                        {% if loop.last and dow != 6 %}
                            <td colspan="{{ 6 - dow }}">&nbsp;</td>
                        {% endif %}
                        {% if dow == 6 %}
                        {% set dow = 0 %}
                        </tr>
                        <tr>
                        {% else %}
                            {% set dow = dow + 1 %}
                        {% endif %}
                    {% endfor %}
                </tr>
                </tbody>
            </table>
        {% endfor %}
    {% endfor %}