Late Charge Interest calculation

Dear Experts ,

We have a question with later change interest calculation

late charge batch - 2025 -12-15

Transaction Date - 2025-09-01

Due Date - 2025-09-02

Original and Overdue Amount - 1000

Days late -104

Interest Days- 122

Fixed interest Rate - 10%

Penalty Charge type - Fixed Amount - 60

Interest calculation formula -Simple

Interest calculation period - Monthly

Interest Days period - 365

Receipt Grace Days - 2 .

Please let us know why Interest days of 122 is taken instead of late days of 104 for interest calculations?

Please refer attachment for Setup and Report

Regards,
Rajiv.