Well, I believe there is a certain 2 year routine/schedule/cycle Mark has and loves. Last year was an exception with the recording of the Bap Kennedy album and Dylan Tour i think. Or maybe he recently started a 3 year routine. With 1 year of to do other projects then bringing out a solo album.
Anyway, normally the two year cycle is something like this:
1. Writing songs and making demos from August to December.
2a. Then in January start recording with band till april.
2b. In April/May mixing of album.
2c. From May till September all activities bringing out album around first week of September
3. September till December promotion activities release new album on TV and radio
4a. January till March practise/rehearsel tour
4b. March/April - August on Tour promoting the new album
I think this cycle has also to do with album sales around december holidays. Like Sinterklaas (Netherlands), Thanksgiving, Christmas.
And that Spring en Summer are the best time to tour. No heavy weather conditions for roadcrew etc.