# Compare Dates
__*DATEDIFF function*__
+ **`DATEDIFF(expr1, expr2)`**: Returns the number of days between two **`DATETIME`** values
  + For example:
    + **`SELECT NOW(), DATEDIFF(NOW(),'2022-02-22'), DATEDIFF('2022-02-22',NOW());`**  
```
tidb> SELECT SELECT NOW(), DATEDIFF(NOW(),'2022-02-22'), DATEDIFF('2022-02-22',NOW());
+---------------------+------------------------------+------------------------------+
| NOW()               | DATEDIFF(NOW(),'2022-02-22') | DATEDIFF('2022-02-22',NOW()) |
+---------------------+------------------------------+------------------------------+
| 2022-10-19 11:36:07 |                          239 |                         -239 |
+---------------------+------------------------------+------------------------------+
1 row in set (0.00 sec)
```

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- DATEDIFF () return the number of days between two days