Weekly Time interval for future dates

I am trying to create a graph from data with dates in the future. However I would like to show the Monday of every week on the x-axes, for next 90 days. For example, the x axes needs to show 8th Oct, 15th Oct, 22nd Oct, 29th Oct and so forth (7 day intervals). I tried using _interval, _timeFilter and $_timeGroup but not getting desired results, while using MYSQL as datasource.
Can this only be done via code changes? Any suggestions? Appreciate any help. Thanks.

not sure, does MySQL support week interval that align like this?