Unfortunately, we are unable to provide time spent per visit or per page for bounce visits.
Time spent per visit is calculated as the time difference between the first page of a visit, and the last one. In case of a bounce visit, there is only one page loaded and we are not able to calculate the time spent. The visit will be closed after 30 minutes of inactivity but we can't know for how long the user was on your site.
In the time spent analyses, bounce visits will be sorted under the entry No duration.