periodOverPeriodPercentDifference(sum(Sales), {Order Date}, WEEK, 1)

Hello,

QuickSight defines Sunday as the start of the week, by default. Upon checking internally, we can make use of the following calculated field formula to group dates by weeks starting on Monday. Please replace {date} with the field name at your end

addDateTime(
    1, 
    'DD', 
    truncDate(
        'WK',
        ifelse(
            extract(
                'WD',
                {date}
            ) = 1, 
            addDateTime(
                -1, 
                'DD', 
                {date}
            ), 
            {date}
        )   
    )
)

There is an existing feature request internally to support custom week start day/date and the internal QuickSight product team is working on it. Unfortunately, we do not have an ETA at the moment for when this feature would be available, but would I recommend you to refer to the following for further updates :

[+] https://aws.amazon.com/it/blogs/aws/category/amazon-quicksight/

[+] https://docs.aws.amazon.com/quicksight/latest/user/WhatsNew.html

Reference: [+] https://stackoverflow.com/questions/55117362/start-week-on-monday-in-aws-quicksight/55857785#55857785

==========

Regarding WoW growth calculation, we can make use of the percentDifference calculated field like the below. Please replace Value, Date with the field names at your end.

percentDifference(Value, [Date ASC], -1)

[+] percentDifference - https://docs.aws.amazon.com/quicksight/latest/user/percentDifference-function.html

Thanks