How do I modify the Planning Date on FB01?

[walkerist]

Hi, I'm trying to modify the BSEG-FDTAG or the Planning Date on FB01.

When the user sets the payment terms, the days/percent field will be populated. <--- There is an existing logic for this.

I'm trying to do is Sum the Days in the Days/Percent field and Baseline Date.

Example.

Payment terms is 123 and the Days/Percent is 10 days/ 10%.

Baseline Date is July 31, 2024.

Planning date should be about August 10, 2024.

I have a custom program named ZPROGSTEPS that calls a step from GBB1. However, when the step was called, the value of BSEG was empty. Hence, no values were added but when I tried to save the document, the date of the Planning Date was equal to the Baseline Date.

I've tried to set the BSEG-FDTAG = '20250101' in my custom program but unfortunately, when I saved the document, the planning date was still equal to the baseline date.

What is the possible solution here? Should I create a step in GBB1 and call that on my custom program?