Using boxplot in a daily time series

From your post it is not clear how the data are organized. Supposing 
they are in a data frame you could use the ~ sintax.

For example:
timeColumn=as.Date("01-01-1970") + 1:500
timeSeries=rnorm(500)
df=data.frame(time=timeColumn, index=timeSeries)

head(df)

     time      index
1 1-01-20 -0.6382554
2 1-01-21 -2.0346649
3 1-01-22 -0.4900213
4 1-01-23  0.7311806
5 1-01-24  0.9386528
6 1-01-25  0.7868129

boxplot(index~months(time), data=df)

Perhaps you would order the 12 boxes according to the months:
monthColumn=ordered(months(df$time), levels= c("January", "February", 
"March",
            "April", "May", "June", "July", "August", "September", 
"October", "November", "December"))
boxplot(df$index~monthColumn)

domenico

Hi all, 

I'm trying to plot my daily time series, with 3650 observations( 10 years), with boxplot but I want 12 boxes, one for each month, can anyone help me doing that.

Best regards

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