Powerquery - appending the same table to itself using differing columns

Question

So I have a list of properties and a list of the next four servicing dates

e.g:

Property| Last    | Next1 | Next2  | Next3  | Next4  |  
123 Road| 01-2019 |03-2019| 05-2019| 07-2019| 09-2019|  
444 Str | 01-2019 |07-2019| 01-2020| 07-2020| 01-2021|  

etc.

I want to see:

Property | Date  
123 Road | 01-2019  
444 Str  | 01-2019  
123 Road | 03-2019  
123 Road | 05-2019  
123 Road | 07-2019  
444 Str  | 07-2019 

etc.

In SQL this would be a union join, in powerquery. I think it's an append, but I'm not sure how to go about it. i.e. how to select columns from a table, then append a table with a different selection. I can append the full table easily, but not certain columns.

Answer 1

Select the date columns and do Transform > Unpivot Columns.

Then you can rename the Value column to Date, remove the Attribute column if you want, and sort as desired.