Hi @thecuon119
If wanting to look at chart with date field and potentially multple months, would suggest using periodoverperiodlast value as suggested above.
Another option, specially if mainly doing daily sales this month vs last month is to 1. create calc field for day num 2. use ifelse functions to calculate the two periods you want to compared. (to-from dates) and formulas as shown here.
This dashboard shows the two options side by side.