(MONEY Magazine) – This article is due in four hours and, frankly, I'm beginning to panic. The research is finished. I just have to write now. So far, unfortunately, I've done everything but: checked my e-mail nine times--no, make that 10--visited with a co-worker, gone back over my notes. Three hours and 45 minutes to go.

If only I'd begun the project knowing as much about the topic as I do now. You, on the other hand, have the benefit of my newfound wisdom. Here's one of the most compelling reasons to keep reading: Whereas the fear of missing deadlines creates a self-fulfilling downward spiral--it causes anxiety, which undermines your productivity, which makes it more likely that you'll miss your deadline, which adds to the anxiety, and so on--learning to manage deadlines can spin a virtuous circle. Deliver what you promise, on time, and you'll shine. You'll gain control over your workload, which is a major component of job satisfaction. You'll feel better about what you're doing and perform better on the job. Heck, you may even get a raise.

Sounds good, right? Just follow these five rules for mastering deadlines.

Nail Down the Details It turns out that much of the anxiety caused by deadlines is rooted in uncertainty about exactly what's expected, and when. According to a Gallup Organization survey of 7 million employees, only about half say that they have a clear sense of what their boss wants them to do. "Expectations and goals change in organizations all the time, and it's rarely clear," says Jim Harter, Gallup's chief scientist for workplace management.

What's more, says Jeffrey Ford, a management professor at Ohio State University and author of Deadline Busting, deadlines are all too often stated in murky terms like "as soon as possible" and "by the end of the month." Those phrases can mean different things to different people, but your boss' definition is the only one that matters. The solution: When your assignment comes, the conversation should end with you restating the details to ensure everyone's on the same page. If your boss doesn't have a specific date in mind, suggest one.

Negotiate Many deadlines are clearly stated, but that doesn't mean you always have to accept them as set in stone. You didn't get hired to say no, of course, but you didn't get hired to do the impossible either. "People say yes to far more than can possibly get done," says Ford. "You have to create circumstances that make success possible."

Most deadlines can be postponed--if you make a compelling case. Suggest a specific alternative date rather than just asking for more time. The best time to counteroffer is when the task is assigned, though you may be able to revisit the issue midway through the project; don't wait until the last minute.

And be sure to explain why you need more time. We often assume our bosses know what we're working on. But they routinely lose track of their employees' workloads, so a reminder is often in order. "The conversation should be about how important the job is and how it fits with the rest of your work, not about how stressed out you are," says Allan Halcrow, author of Gray Matters: The Workplace Survival Guide. In the end, you might not get all of what you request, but you'll likely get some of it.

Break the Work into Pieces A common--and sound--rationale for breaking a project into its component parts is a psychological one: to make a seemingly overwhelming task feel more manageable, and thus avoid paralyzing anxiety. But according to Dottie Nichols, the standards manager at the nonprofit Project Management Institute, there's strategic value in doing so as well: It enables you to see how the different parts of the job depend on one another. In order to get to Task B, for instance, do you have to complete Task A? Or can you do them independently? Understanding these "dependencies," Nichols says, will help you plot out your work schedule and spot logjams before they happen.

Unleash Your Inner Pessimist How long will a project, or piece of a project, take? Make your best guess--and then tack on another 50%. The fact is, studies have consistently found that we underestimate how long things will take. The less familiar the task, the more skewed our estimation. Psychologists call this "the planning fallacy." We tend to exaggerate our own talents, which leads us to believe that we will overcome challenges and avoid potential pitfalls in completing our work. To keep this "delusional optimism" in check, Nobel-prizewinning behavioral economist Daniel Kahneman and collaborator Dan Lovallo, in a recent Harvard Business Review article, recommend using outside reference points--like how long similar tasks have taken you in the past, or how long other people spend on similar projects--to guide your estimate. If, for example, several other companies brought a comparable product to market in 12 to 14 months, little suggests that your team will be able to do it in eight, other than delusional optimism.

Get Out of Your Own Way The only obstacle left in your path is, well, you. According to a recent survey by America Online and Salary .com, the average worker admits to wasting more than two hours a day, not including lunch. Though we all procrastinate, a handful of simple measures can minimize the wasted time. If you can, turn off your e-mail program and forward your calls to voice mail for certain hours of the day, suggests executive coach Lisa Aldisert. Build time into your schedule to return messages, and stick to your plan. Move the tasks you tend to put off to early in the day, before your attention gets pulled in other directions. And make sure to do your own work before helping co-workers. Sure, helping others can buy you sympathy if your own work is late, but fulfilling your own professional promises on time is reward in itself. A reward I'm now enjoying, in fact. Over to you, boss.