ABAP Date Difference: Calculate Days, Months, and Years

How to Calculate Date Difference in SAP ABAP

In SAP ABAP, you can calculate the difference between two dates (in days, months, or years) using different methods.

1. Simple Date Difference in Days

ABAP allows you to directly subtract two date fields.

DATA: lv_date1 TYPE sy-datum,
      lv_date2 TYPE sy-datum,
      lv_diff  TYPE i.

lv_date1 = '20240310'.  " 10th March 2024
lv_date2 = '20240301'.  " 1st March 2024

lv_diff = lv_date1 - lv_date2.

WRITE: 'Difference in days:', lv_diff.

✅ Works with standard date format (YYYYMMDD) ✅ Returns positive or negative values depending on date order

2. Difference in Months and Years

For months and years, you can use the function module HR_HK_DIFF_BT_2_DATES.

DATA: lv_date1    TYPE sy-datum,
      lv_date2    TYPE sy-datum,
      lv_years    TYPE i,
      lv_months   TYPE i,
      lv_days     TYPE i.

lv_date1 = '20240310'.  " 10th March 2024
lv_date2 = '20210305'.  " 5th March 2021

CALL FUNCTION 'HR_HK_DIFF_BT_2_DATES'
  EXPORTING
    date1 = lv_date1
    date2 = lv_date2
  IMPORTING
    years = lv_years
    months = lv_months
    days = lv_days.

WRITE: 'Difference:', lv_years, 'Years,', lv_months, 'Months,', lv_days, 'Days'.

✅ Accurate calculation of years, months, and days ✅ Handles varying month lengths

3. Using `DAYS_BETWEEN_TWO_DATES` Function Module

If you’re dealing with factory calendars, you can use:

DATA: lv_days TYPE i.

CALL FUNCTION 'DAYS_BETWEEN_TWO_DATES'
  EXPORTING
    date_1 = '20240310'
    date_2 = '20240301'
  IMPORTING
    days   = lv_days.

WRITE: 'Days difference:', lv_days.

✅ Useful when working with business days ✅ Considers factory calendar settings

4. Using Class `CL_ABAP_TSTMP` for More Precision

If you’re working with timestamps and need precise time differences, use:

DATA: lv_date1 TYPE timestamp,
      lv_date2 TYPE timestamp,
      lv_diff  TYPE int8.

lv_date1 = '20240310120000'.  " 10th March 2024, 12:00:00
lv_date2 = '20240309180000'.  " 9th March 2024, 18:00:00

lv_diff = cl_abap_tstmp=>subtract(
            i_tstmp1 = lv_date1
            i_tstmp2 = lv_date2 ).

WRITE: 'Difference in seconds:', lv_diff.

✅ Precise to the second ✅ Works with timestamps (YYYYMMDDHHMMSS)

Best Method to Use?

Scenario	Recommended Method
Difference in days	`date1 - date2`
Difference in years, months, and days	`HR_HK_DIFF_BT_2_DATES`
Difference in business days	`DAYS_BETWEEN_TWO_DATES`
Difference in timestamps (seconds)	`CL_ABAP_TSTMP=>SUBTRACT`