DB2: To find when a table was ALTERed

 SELECT 

    TABSCHEMA AS SCHEMA_NAME, 

    TABNAME AS TABLE_NAME, 

    ALTER_TIME AS LAST_MODIFIED_TIME

FROM 

    SYSCAT.TABLES

WHERE 

    TYPE = 'T' 

    AND TABSCHEMA NOT LIKE 'SYS%' -- Exclude system schemas

ORDER BY 

    ALTER_TIME DESC;