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| id | on_date | off_date |
|---|---|---|
| 1 | 2020-09-10 | null |
| 2 | 2020-09-09 | null |
| 3 | 2020-09-08 | null |
| 4 | 2020-09-09 | 2020-09-10 |
| 5 | 2020-09-08 | null |
| count | date |
|---|---|
| 2 | 2020-09-08 |
| 4 | 2020-09-09 |
| 4 | 2020-09-10 |