Build Plan weekly buckets not as per the Plan Calendar

Summary:

We are using build plan to review capacity at weekly levels. Customer is based out of Middle east. Hence they want to have Sunday as the first day of the week.

We have created a manufacturing calendar and using the same for material plans. But when I look at the build plan (in layout, I have selected weekly bucket), it shows Monday as the first day of the week. I want to know which configuration would help to make sure that it also uses Sunday as the first day of week, as we have in other tables (Material Plan).