Function is_date

The function checks strings for being a date.
You might pass a second parameter to use a format string. Without the format, the default format of PostgreSQL is used.

There has been a behaviour change in PostgreSQL 10. A conversion is now handled strict, in previous versions the conversion tried to calculate dates.

Examples

/**
 * Parameter is in PostgreSQL default format
 */
SELECT is_date('2018-01-01') AS res;

Result:

res
t

SELECT is_date('2018-02-31') AS res;

Result:

res
f

/**
 * Parameter is in PostgreSQL German format
 */
SELECT is_date('01.01.2018', 'DD.MM.YYYY') AS res;

Result:

res
t

SELECT is_date('31.02.2018', 'DD.MM.YYYY') AS res;

Result:

res
f