# Compare Dates
__*DATEDIFF function*__
+ `DATEDIFF(expr1, expr2)`: Returns the number of days between two DATETIME values
  + For example:
    + `select DATEDIFF(now(),'2022-02-22'), DATEDIFF('2022-02-22',NOW());`  
```
tidb> SELECT DATEDIFF(now(),'2022-02-22'), DATEDIFF('2022-02-22',NOW());
+------------------------------+------------------------------+
| DATEDIFF(now(),'2022-02-22') | DATEDIFF('2022-02-22',NOW()) |
+------------------------------+------------------------------+
|                          -44 |                           44 |
+------------------------------+------------------------------+
1 row in set (0.00 sec)
```

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