Use Grouped Exposed Filter
Using a Grouped Exposed Filter for the
Authored on field is the quickest and easiest way to filter out by academic year.
When you Expose a Filter, you can choose between
Single filter and
If you choose Grouped filters you can define your own items for the Exposed filter. In your case two academic years would be configured like this:
I haven't included time but you probably should to make sure that content created on July 31 and August 1 doesn't get exluded. Maybe something like
2017-08-01 00:00:00 and
2018-07-31 23:59:59 would work.
Add as many entries as you have academic years. Then when viewing your Views results choose the appropriate academic year option:
I've noticed grouped filters have some bugs in D8 when dealing with taxonomy terms, but I haven't noticed any problems with AuthoredOn field.
Content: Created year + month
If you include this Contextual Filter and choose to
Display a summary:
you get links of months and years you click through to see content posted within those dates:
If that alone isn't enough maybe that can inspire you to create a similar custom Contextual filter with a bit more logic inside to do the same but for a configurable set of periods.