Possible to set 2 data fields within 1 select option? I have the following code in my form, but I'd like to also save the eventDate of the selected entry into a separate date field to enable sorting/selection later.

&lt;label for="eventName"&gt;Event
&lt;select id="eventName" name="fields[eventName]"&gt;  
  &lt;option value=""&gt;select from list&lt;/option&gt;
    {% set events = craft.entries.find({section:'events,activities', eventDate : "&gt;= " ~ now.w3cDate() , order:'eventDate'}) %}
    {% if events %}
        {% for entry in events %}                
            &lt;option value="{{ entry.eventDate.format('D j M') }},{{ entry.eventName }}"&gt;{{ entry.eventDate.format('D j M') }},{{ entry.eventName }}&lt;/option&gt;
        {% endfor %}
    {% endif %}
&lt;/select&gt;            
&lt;/label&gt;
You could use the Preparse plugin to create a field that is automatically updated with the eventDate value whenever the entry is saved. It wouldn't be a datetime field, but if you stored the timestamp (i.e. {{ dateString|date('U') }}) it'd be easy to use as such.

Another option is to have an hidden input in your form for the eventDate datetime field, and use JavaScript to set its value whenever the &lt;select&gt; input changes (i.e. listen for the change event for the latter, in your JS).

The third option would be to write a plugin which listens to the entries.beforeSaveEntry event in order to set the eventDate value from the dropdown field.