Hi all, I've got a question predictive models.
I've got several months of numbers for different categories and I want to create a predictive model.
There are two sets of drivers, a trend in numbers over time, and 2nd seasonality (example ..average gain/loss between May and June each year)
It seems like there would be a tried and true formula or function to predict the future numbers but I haven't found it.
I was thinking something I could pass the range and interval for seasonality, in this case 12.

Any ideas?


Thanks
J