Series frequency for book

[jlivsey]

Series frequency for book

[christophsax]

I think monthly and quarterly series will make most of the examples. But I think we will have to talk about other frequencies somewhere. Not sure if we do that at the same place, but there are two groups of other frequencies:

1. Frequencies like 2 (or ?) that are supported by some parts of X-13. This is more like a larger footnote but should be mentioned somewhere. I don't think that we need to take care of them in the usual examples.

2. Daily Frequencies and stuff that is not supported by X-13. This probably should have it's own chapter and give some good ideas and references for how to proceed.

[christophsax]

I will add a caveat on the frequencies somewhere in the beginning. Monthly and quarterly should be the focus. Let's decide much later if we want to have a chapter on daily adjustment at the end of the book.