SELECT YEAR(STR_TO_DATE(field_data_field_event_date.field_event_date_value, '%Y-%m-%dT%T')) AS year, COUNT(YEAR(STR_TO_DATE(field_data_field_event_date.field_event_date_value, '%Y-%m-%dT%T'))) as count
FROM {node} node LEFT JOIN {field_data_field_event_date} field_data_field_event_date ON node.nid = field_data_field_event_date.entity_id
// get months for the current year, and number of events in each month
$result_month=db_query("
SELECT DATE_FORMAT(STR_TO_DATE(field_event_date_value, '%Y-%m-%dT%T'), '%m') AS month, COUNT(MONTH(STR_TO_DATE(field_event_date_value, '%Y-%m-%dT%T'))) as count
FROM {node} node LEFT JOIN {field_data_field_event_date} field_data_field_event_date ON node.nid = field_data_field_event_date.entity_id
WHERE node.type = 'uw_event' AND node.status = 1 AND YEAR(STR_TO_DATE(field_event_date_value, '%Y-%m-%dT%T')) = :display_year