Конвертим activity date с помощью CONVERT STAMP

CONVERT TIME STAMP <fs_itab>-issue_data TIME ZONE activity_tz INTO DATE DATA(activity_date) TIME sy-uzeit.

1	CONVERT TIME STAMP <fs_itab>-issue_data TIME ZONE activity_tz INTO DATE DATA(activity_date) TIME sy-uzeit.

способ №2

CONVERT DATE p_dat1 INTO TIME STAMP
     l_tmstp TIME ZONE sy-zonlo.

1 2	CONVERT DATE p_dat1 INTO TIME STAMP l_tmstp TIME ZONE sy-zonlo.

смотрим в дебаге на sy-subrc

sy-subrc	Meaning
0	Time stamp was converted into the local time of the specified time zome and assigned to the target fields.
4	Time stamp was assigned to the target fields without conversion into the local time.
8	Time stamp could not be converted since the specified time zone is not available in database table TTZZ.
12	Time stamp could not be converted since time_stamp contains an invalid value.