How to customize exposed filter for date field?
You can create your own form controls to send his values to exposed filters. For example, create your own select list inside a exposed filters template (views-exposed-form.tpl.php). This select list can have your desired options with respective values, according is needed in the exposed filter, for example:

&lt;select id="edit-date" class="form-select" name="date"&gt;
&lt;option value="-1 day"&gt;New members&lt;/option&gt;
&lt;option value="-7 day"&gt;Members within 1 week&lt;/option&gt;
&lt;option value="-30 day"&gt;Members within 1 month&lt;/option&gt;
&lt;option value=""&gt;All members&lt;/option&gt;
&lt;/select&gt;


Also, if you need a more complex behavior, you can alter view's queries with query_alter hook. This answer is an example of how to use query_alter with a custom select list.

I hope information be useful.