How can i filter a datetime column in informix with a date

I’d like to filter a datetime column in informix 12.10.

I got the following “test” table

name	insert_date	create_date
…	2022-04-06 11:03:22.000	….
…	2022-03-02 12:03:22.000	….
…	2021-02-04 11:15:22.000	….
…	2021-01-05 11:03:22.000	….

My approach is the following

SELECT * FROM test where insert_date < "01.01.2022"

I got the error: SQL-Error [IX000]: Non-numeric character in datetime or interval.

How can i filter a datetime column with a date (without time) in informix?

Answer

According to the documentation that should be¹

select *
  from TEST
 where INSERT_DATE < DATETIME (2022-1-1) YEAR TO DAY

¹ Assuming that the data type of column INSERT_DATE is DATETIME YEAR TO FRACTION.