Advertisements I have the following dataframe, df: structure(list(x = structure(1:961, levels = c("2019-11-30", "2019-12-01", "2019-12-02", "2019-12-03", "2019-12-04", "2019-12-05", "2019-12-06", "2019-12-07", "2019-12-08", "2019-12-09", "2019-12-10", "2019-12-11", "2019-12-12", "2019-12-13", "2019-12-14", "2019-12-15", "2019-12-16", "2019-12-17", "2019-12-18", "2019-12-19", "2019-12-20", "2019-12-21", "2019-12-22", "2019-12-23", "2019-12-24", "2019-12-25", "2019-12-26", "2019-12-27", "2019-12-28", "2019-12-29", "2019-12-30", "2019-12-31", "2020-01-01", "2020-01-02", "2020-01-03", "2020-01-04", "2020-01-05", "2020-01-06", "2020-01-07", "2020-01-08", "2020-01-09", "2020-01-10", "2020-01-11",… Read More Sum a daily variable per month taking into account the year