As I manage my stock investment portfolio in Google Sheets, I need to see its evolution over time, for example, in the last year. However, the computation for daily evolution is resource-consuming and might cause performance issues for the spreadsheet. As an alternative, I compute only the weekly evolution of the investment portfolio for the last year. For each week, I compute only the portfolio's value at the end of the Friday. For that, I need a Google Sheets formula to return the last Friday for a given date. This post explains how I do that with the WEEKDAY formula in Google Sheets.
