When viewing an archived Mail in Arctera Personal Archive, the date stamp of the message will display in the top right corner, as seen here:

However, if the "Print this Message" button is selected, a separate window will open displaying the message, and the date and time are now no longer visible, as seen here (using FireFox as an example):

This is expected behavior, as the current design of Arctera Personal Archive does not display the date/time of the message. If printed, the date will still be missing from display as this is the current design of Arctera Personal Archive.
If it is necessary to display the date and time, simply click "Save This Message" to download a restored version of the email to the local computer.

This will allow Outlook (or any other locally employed mail client) to open the message natively, which includes the date and time, as seen here:

Any printing of the message would print in the mail client's native formatting, which typically includes date and time.
Note: There may be some time differences between the time of the local mail client and the time of the Arctera SMTP server that originally received the message; so time disparities may occur between Arctera Personal Archive displayed time of the mail and the natively downloaded message.
How to have the Date and Time Stamp of an Archived Message Display When Printed from Personal Archive