You would think that PM would have learned about the feature that quite a few email systems have to send an email at a particular time! (e.g. Outlook has "Do not deliver before" option).
The last place I worked, 18 months ago, that required after-hours logs still used pen and paper. Plus, they left the log books out all the time, so it was easy when you signed in to see who else was coming in after hours, going back weeks sometimes.