[Vlad1k]

Anywhere from 24 hours to 48 hours.
It says so in the Help Docs.

[Vlad1k]

Due to the influx of requests we get per day and the inconvenience of the different Time Zones we have, we cannot guarantee that your e-book will be reviewed swiftly. Our operations rely greatly on the workload we have. As you understand, we, the leaders, cannot control the third step mentioned above; this causes the usual delay. Please wait for a maximum of seven days for your e-book to be reviewed. You will be receiving the review confirmation post on your thread the moment your e-book is in the process of reviewing.
Feel free to ask us any questions with regard to your review if after seven days have gone, and yet, your review has still not been produced.

Contact the Reviewers after seven days if you still haven't gotten it reviewed.

[+Reckless]

Reviews are normally completed within 5 days.