SELECT
    # Change the interval based on UTC to show on specific timezone
    date_format(date_sub(o.created_at, INTERVAL 7 HOUR), "%l:%i %p") `Time in PST`,
    count(*) OPM
FROM sales_flat_order o
# Time from the DB - last 3 hours
WHERE o.created_at > DATE_SUB(NOW(), INTERVAL 3 HOUR)
AND o.created_at < NOW()
AND o.store_id='1374'
GROUP BY HOUR(o.created_at),MINUTE(o.created_at)
ORDER BY o.created_at ASC;