Please list the time when event no.2 happened on a vivo device.
time refers to timestamp; event no. refers to event_id; event_id = '2'; vivo device refers to phone_brand = 'vivo';
SELECT T1.timestamp FROM events AS T1 INNER JOIN phone_brand_device_model2 AS T2 ON T1.event_id = T2.device_id WHERE T2.phone_brand = 'vivo' AND T1.event_id = '2'