All time-data is always stored in our database in UTC.
By default, we convert any visible timestamps to the local timezone of the computer being used to view that timestamp.
This counts for all time data including, assignment due dates, zyLab time windows, zyLab submission timestamps, the activity recording tab and so on.
For example, the activity below is due at 11:59pm Pacific but the student is viewing the assignment from the East coast so she sees that the assignment is at 2:59am local.
If desired, an instructor can set a timezone for their zyBook on the "Manage class" page.
To get to the "Manage class" page. Find the orange "Manage" button on the "My class" tab on the homepage of the zyBook.
Next, scroll down to "Time zone setting" and select a timezone.
When a timezone is set, students and instructors will see all time data in the timezone that is set on the book. A timezone indicator will also be present. Note that in the sample book from the example above, the timezone was sent to Pacific so the student now sees that the assignment is due at 11:59 PM PDT even though she is still viewing from the East Coast.