ABAP Add Months to Date: SCAL Class & Function Modules

In SAP ABAP, adding months to a date is slightly more complex than adding days because you must consider varying month lengths. Here are different ways to add months to a date:

1. Using SCAL Class (Recommended for Newer Systems)

DATA: lv_date    TYPE d,
      lv_newdate TYPE d.

lv_date = sy-datum.  " Current date

lv_newdate = cl_abap_datfm=>add_to_date(
              i_date   = lv_date,
              i_months = 2 ).  " Add 2 months

WRITE: lv_newdate.

✅ Best practice for modern ABAP
✅ Handles month-end cases properly (e.g., from 31st Jan to 28th/29th Feb)

2. Using RP_CALC_DATE_IN_INTERVAL Function Module

DATA: lv_date    TYPE sy-datum,
      lv_newdate TYPE sy-datum.

lv_date = sy-datum.

CALL FUNCTION 'RP_CALC_DATE_IN_INTERVAL'
  EXPORTING
    date      = lv_date
    days      = 0
    months    = 2  " Add 2 months
    signum    = '+'  " Add instead of subtract
  IMPORTING
    calc_date = lv_newdate.

WRITE: lv_newdate.

✅ Works in older versions of SAP
✅ Supports both months and years adjustments

3. Using DATE_COMPUTE_DAY Function Module (Alternative)

DATA: lv_date    TYPE sy-datum,
      lv_newdate TYPE sy-datum.

lv_date = sy-datum.

CALL FUNCTION 'DATE_COMPUTE_DAY'
  EXPORTING
    date  = lv_date
    months = 2
  IMPORTING
    result = lv_newdate.

WRITE: lv_newdate.

✅ Simple but limited in functionality
⚠️ May not handle complex month-end cases correctly

Which Method to Use?

• ✅ Use SCAL (CL_ABAP_DATFM=>ADD_TO_DATE) for best performance and compatibility.
• ✅ Use RP_CALC_DATE_IN_INTERVAL if you need compatibility with older systems.
• ✅ Use DATE_COMPUTE_DAY as a last resort.