Entity query to select current dates
Having actually read the fieldCondition documentation the fourth property turns out to be $delta_group which allows specifying dependent conditions. So it turns out all I needed was the below:

$current_date = date("Y-m-d H:i:s");
$query = new EntityFieldQuery();
  $query-&gt;entityCondition('entity_type', 'node')
    -&gt;entityCondition('bundle', RD_PRIZE_DRAW_NODE_TYPE);
    -&gt;fieldCondition('field_rd_prize_draw_dates', 'value', $current_date, '&lt;=', 1)
    -&gt;fieldCondition('field_rd_prize_draw_dates', 'value2', $current_date, '&gt;=', 1);
    -&gt;execute();