Yep, create a calculated column and do the following, I pointed my column at the created date column for an example. I didn't know the order you wanted so I did 'year''space''month'.
=TEXT([Created],"yyyy"&" "&"mmmm")
(show data as single line of text)
The result displays: 2017 September
Also you can play with the result formula to change how the data is calculated.
yy = 17
yyyy = 2017
mm = 09
mmmm = September
etc.
More formulas can be found in your built in SharePoint help, just click on the question mark in the top right corner of the site and search for "formulas" to see an article with more formulas for sharepoint. Here is the article from the support website. https://support.office.com/en-US/article/Examples-of-common-formulas-in-SharePoint-Lists-D81F5F21-2B4E-45CE-B170-BF7EBF6988B3