hive datediff()

Hive's `datediff()` function calculates the number of days between two given dates. It takes two arguments, the end date and the start date, and returns the difference in days.

Here's an example usage of `datediff()` in Hive:

SELECT datediff('2022-01-01', '2021-01-01') AS days_diff;

In this example, `datediff()` calculates the number of days between January 1, 2022, and January 1, 2021. The result will be 365 days.

Please note that the `datediff()` function in Hive considers only the date portion of the input and ignores the time portion.