Archive date display

When clicking on a date in the calendar the journals for that date appear on a page.
At the top of the page, under the blog title and before the first journal, the following appears:

Archive (07 June 2017)

How can I change the format for the date so that it appears as June 7, 2017 ?
I can't seem to find it in admin settings or any of the code I looked at.

I notice that this, Archive (07 June 2017), is also what is displayed in the web page title.

Thanks