1. Choose to Accept the submission by checking the box next to the submission in the Submissions List and then clicking the green check mark button at the top of the list. You can also accept the submission within the Submission Details page by clicking the status button in the upper right-hand side of the page (the button should say New or In-Progress). You then select Accept.
2. A dialog box will open that states You are about to ACCEPT 1 submission. Enter the Publication Date in the appropriate box.
3. To edit or delete the Publication Date, go to the Submission Details page of the submission you want to edit. Select the calendar icon to add or edit the publication date.
Read this article for more information on the Calendar feature.