[Plugin: Post Expirator] Default expiration time

Hi,
I noticed that the expiration time is set up by default about 9 hours later than the time you are writing the post.
Is there a way to set up a fixed expiration time (at 11.35pm of the current day obviously)?

So when you enable it (in the admin post page) you get the time on 11.35pm right away.

Please let me know your thoughts.

Thanks