i have a daily time series of several years. Graph & CSV-file
So far i could figure out with an based on an acf graph and this method:
timeSeriesObj = ts(x,start=c(1999,1,1),frequency=7)
fit <- tbats(timeSeriesObj)
seasonal <- !is.null(fit$seasonal)
seasonal
returns: TRUE
timeSeriesObj = ts(x,start=c(1999,1,1),frequency=365.25)
fit <- tbats(timeSeriesObj)
seasonal <- !is.null(fit$seasonal)
seasonal
returns: TRUE
that i have a weekly as well as an annual seasonality.
How do i look for monthly seasonality? Is it a legit way to sum up all days of a month so i get 12 months a year and then check the acf graph again?
My final goal would be to estimate the different seasonal factors and remove them from the data in order to analyse the effects of different dates as for example easter or 4th of july.