Variante 1 (Monatskalender, Monat und Jahr wählbar)
DATA: lv_dat TYPE sy-datum.
CALL FUNCTION 'F4_DATE'
IMPORTING
select_date = lv_dat
EXCEPTIONS
calendar_buffer_not_loadable = 1
date_after_range = 2
date_before_range = 3
date_invalid = 4
factory_calendar_not_found = 5
holiday_calendar_not_found = 6
parameter_conflict = 7
OTHERS = 8.
Variante 2 (Jahreskalender, scrollbar)
DATA: lv_dat TYPE sy-datum.
CALL FUNCTION 'POPUP_CALENDAR_SDB'
EXPORTING
sel_day = abap_true
focus_day = sy-datum
IMPORTING
begin_date = lv_dat.