how to identify greater than one changes of a field in one day from mainframe DB2 table?

For Example i have a field EMP_CODE_NO in EMP table.The Key for the table is EMP_ID. The EMP_CODE_NO is getting changed from 10 to 20.In a same day, it may get changed from 20to 50.How to identify this case from that table by writting SQL query?

Allowable values in EMP_CODE_NO field is 10,20,30,40 and 50.