What is the most elegant way to split data and produce seasonal boxplots?

Question

I want to produce seasonal boxplots for a lot of different time series. I hope that the code below clearly illustrates what I want to do.

My question is now, how to

Answer 1

You are better off picking out the month names directly with the "%b" format and using an ordered factor and the formula interface for boxplot:

DF$month <- factor(strftime(DF$Time,"%b"),levels=month.abb)
boxplot(Data~month,DF)