✅ Simple Mysql solution with SUM, GROUP BY
\nSELECT event_day AS day, emp_id, SUM(out_time - in_time) AS total_time\nFROM Employees\nGROUP BY day, emp_id;\n
```\nSELECT event_day AS day, emp_id, SUM(out_time - in_time) AS total_time\nFROM Employees\nGROUP BY day, emp_id;\n```
['MySQL']