R – native and ggplot boxplots

date <- seq.Date(as.Date("2013-06-01"), as.Date("2014-05-31"), "days")
set.seed(100)
x <- as.integer(abs(rnorm(365))*1000)
df <- data.frame(date, x)
boxplot(df$x ~ months(df$date), outline = FALSE,las=2)
library(ggplot2)

ggplot(df) +
  geom_boxplot(aes(reorder(format(date,'%B'),date),fill=format(date,'%Y'),x)) +
        xlab('Month') + guides(fill=guide_legend(title="Year")) +
        theme(axis.text.x = element_text(angle = 45))