I have daily data for 3 years. This sales data is of seasonal nature as business has spikes and downfall by month. Also, sales differ by each day of the week. for example, monday in general in a month tend to have similar pattern.
I have used ARIMA and created a matrix of month dummy variables and day of week dummy variables and have passed that in ARIMA. however i hit the bottom when i couldn't reconvert differenced stationary number forecasts into the actual sales metric. Posted here already
I have also tried dummy regression using sales as dependent variable and 11 month dummy variables and 6 day of week dummy variables. i abandoned this as R square was low at 48% and MAPE from the forecasted results was more than 20%
Edit: I have tried auto.arima as well. My question: What technique can i use for forecasting sales for next 365 days? that will consider this month of the year and day of the week seasonality?