Per T134060#2255302 2016-Q4 obviously means April-June 2016 (and assuming that July-September 2016 is then either 2016-Q1 or 2017-Q1)
I can understand, that WMF's fiscal year is July-June and therefore quarters obviously have to stay this way, however, we still can make project names less confusing for those who are not aware of it, not even speaking about the first-sight.
I would encourage rather using either month delimitation (2016-Apr-Jun etc...) or FY-double-year marking (2015-2016-Q4 etc...) or whatever else which will be clear straight away from the first sight...