So just how much is "sufficient time"? There is no one single answer to this, of course, because every assignment poses its own challenges, and every student works at his or her own pace. In general, though, the more complex an assignment, the more time you should budget for it. In this website's Types of Assignments-section, we listed various categories of written assignments, in a sort of reverse-hierarchical order of complexity, starting from the least, and ending with the most complex. The assignments ranged from narrative history and response papers (least complex) via annotated bibliographies, book reviews and historiographic essays (increasingly complex) to research papers (most complex). The more complex an assignment, the more time you will need to complete it.
Be smart: budget time to spare! Consider the following suggestions:
Follow Basic Rules # 1 and # 2, listed at the top of this page, and consider the recommendations above, and hopefully you'll encounter no time problems.