org-journal-read-entry Cannot Find Journal Entry

#### The Setup

Following the advice of the README, I am customizing my org-journal-file-format and org-journal-file-pattern variables.  This seems to be working correctly and the days with journal entries are highlighted in calendar mode.  The settings for each follow:

    (setq-default org-journal-file-format "%Y%m%d.org-j")
    (setq-default org-journal-file-pattern "[0-9]\\{8\\}.org-j$")

#### The Problem

In calendar view, if I hit 'j' to view the journal entry, I receive the message "No journal entry for this date".  Clearly, this is because org-journal-read-entry has hard-coded logic to look for a file in YYYYmmdd format.

I would like to try my hand at working on a patch for this issue, but I was curious how you think I should go about it.  Should we provide some custom function the user can define to  lookup the file?  Can you think of a better solution?