Compare current day performance to a specific day in the past

We had a peak in transactions volume on 6/30 and i am looking to compare everyday with the peak day. Was trying to use ‘Compare with x days ago’ attribute but i need to update the x every day to keep it locked onto 6/30. Is there a way we can provide a past date to compare against?

You want to compare a number or have a timeseries chart with compare?

I want to compare a KPI from current day to a previous peak day and see how current day is trending against this previous peak day.