Oracle solution with TO_CHAR func
\nSELECT \n    TO_CHAR(event_day, \'YYYY-MM-DD\') day, \n    emp_id, \n    SUM(out_time - in_time) total_time\nFROM Employees\nGROUP BY event_day, emp_id\n
```\nSELECT \n    TO_CHAR(event_day, \'YYYY-MM-DD\') day, \n    emp_id, \n    SUM(out_time - in_time) total_time\nFROM Employees\nGROUP BY event_day, emp_id\n```
['Oracle']