@KB77 depending on your Canvas permissions, if you click on the user icon/avatar you will be offered a "User Account Details" option which lists enrolments and page views. The latter lists URLs and is filterable by date.
It is possible to get a feel for the student's activity around the time of the assessment but I would take that data with a 'pinch of salt'. A lot of navigation handling seems to be scripted within the page, so wouldn't necessarily show up as 'hits'.
A submission will show as a URL with a tick/check in the participation column, and the time shown here should correspond to the submission time shown in Speedgrader. This is distinct from viewing/opening the assignment. I would suspect that what shows as a file being loaded (which a student is at liberty to change before submission) is being handled on the host computer side rather than in Canvas.
In our institution what matters is when the student hits the 'submit' button, and our academic adjudicators have little sympathy for students who wait until immediately before the submission deadline to submit. Further, our assignments all carry a warning about ensuring a good connection, and avoiding final submission via mobile.
As a postscript on Data Protection, I'm uncomfortable with the level of information available in User Account Details automatically being available to teachers - amongst other privacy issues (the download includes IP address) it would allow submission anonymity to be circumvented by reference to the submission time.
