Querying dates with different timezones at db and application level
Check this:

SELECT created_at,
convert_tz(created_at , '+00:00', '-07:00'),
convert_tz(created_at , 'UTC', 'America/tijuana')
FROM 
    (SELECT TIMESTAMP '2016-06-01 09:26:50' as created_at FROM DUAL) orders;


If the last column is null , see prerequisites at https://mariadb.com/kb/en/mariadb/convert_tz/