Convert date to Month inthe start routine

Hi all,

Is there a way to convert date to month in 3.5 BW version?  I need this code in the start routine to create an internal table and for the field mapping.

If the document date is 20140801 then month/year 201408. There is a month to month mapping to populate a field. Because of performance, we plan to create an internal table in the start routine and later read it in the update routine for charac field.  Source contains only date and month needed for the mapping. This month derivation will based upon begin and end date for month not period.

Thanks,

Di