Hello! I have data.frame with column class POSIXct: data[, 1] <- as.POSIXct(data[, 1], format = "%d.%m.%Y %H:%M") I need to write custom axis for plot where can be ex.: January (mean of january's temperature). List of month I get as table(months(data[, 1])). What is next step? Thanks. -- Всего наилучшего! greg [at] dobroe [dot] ru Григорий.