Generation of custom Calendars in Power Query

In my previous post I described how to build relative date functions in Power Query

Associated topic is a generation of Calendar table for Excel Data Model (aka PowerPivot) where better to have only necessary period of time. And certain list of dates in some cases, e.g. ends of last X month if we analyse month results.

Assume that we have model with sales of previous month. Quite often in such model we don’t need dates of previous of future year and when we refresh such model in the beginning of new month our Calendar should be refreshed as well.

I took idea of calendar generation from post on http://powerpivotpro.com, thanks to Matt Allington.

Functions List.Dates and List.Generate can help us get initial list of dates and then extend it to useful calendar with long month names, short month names etc.