You've submitted, the page says the report is generating, and the deadline anxiety has nowhere to go. Here are the realistic timelines for every scenario — including the one nobody warns you about, which regularly ambushes students who resubmit an hour before the cutoff.
First submission: usually minutes
For a typical essay submitted to an assignment for the first time, the similarity report generally lands within a few minutes — longer for very large files, submissions right at a popular deadline, or peak weeks of the semester, where it can stretch toward an hour. If your assignment shows nothing after several hours, something's usually wrong with the submission itself (unreadable file, scanned images) rather than the queue.
Resubmissions: the 24-hour trap
This is the one to plan around. When an assignment allows resubmission, Turnitin regenerates the report — but repeated resubmissions trigger a waiting period of up to 24 hours before the new similarity report appears. Students discover this by resubmitting a final tweak the night before the deadline and watching the report stay pending past it. If your workflow is draft → check → revise → resubmit, budget a full day per cycle on the university side — or do the iteration outside the assignment (a draft slot or a proper pre-check) and submit once, clean.
The AI score: instant, but not for you
The AI writing analysis appears alongside the report in the instructor's view — there's no separate wait worth planning for. The relevant delay for students is different: you typically never see the AI score at all, on any timeline. The similarity score may be released to you depending on assignment settings; the AI indicator is instructor-only.
What controls whether you see anything
Every student-visible timing question runs through the instructor's assignment settings: whether you can view the similarity report, whether it's visible immediately or only after the due date, and whether resubmission is allowed at all. If your report "never arrived," check the assignment description before assuming a technical failure — "students can view: no" is the most common explanation.
Checking on your own clock
If the waiting is the problem — the 24-hour resubmission lag, the after-grading visibility, the invisible AI score — a real Turnitin check exists precisely to put the timeline in your hands: both reports, typically in about 10 minutes (occasionally up to an hour in busy periods), visible to you and nobody else, in no-repository mode so the check doesn't interact with your later submission. Iterate as many times as you have credits, on your schedule instead of the LMS's.