While we’re all still reeling from John Stewart’s announcement that he’s leaving The Daily Show, you’ve got to give the guy credit. It’s not easy to step away from such an amazing, sought-after gig. But he’s a smart guy who knows when to say “when.” He’s had ideas for new opportunities, felt himself getting “restless” and decided to go out on a high note.

We can learn something from Stewart’s gutsy move. It can be challenging to leave a stable, decent-paying job and venture into unknown territory. But sometimes, for the sake of your career (or your sanity), you just have to take the plunge.

So when should you say “when?” Here are five tell-tale signs that it’s time for you to move on.

1. You’ve Gone as Far as You Can Go

This has a tendency to happen in smaller companies and organizations. The benefit of being a big fish in a small pond is that you’re often given more opportunities and decision-making power. But, the drawbacks are that there’s not always a “next step,” and there are few higher-ups from whom you can learn.

It’s tempting to stay on longer than you should in these cases, either out of comfort or a sense of obligation or loyalty. But, if you’re truly maxed out and not learning anything new, you’re wasting time you could be spending on new endeavors.

2. You’re Bored out of Your Mind

There certainly are personality types that are perfectly content with performing the same job duties day after day, year after year. Some people thrive on consistency and ritual. But, if you’re a person who needs variety to stay engaged with your work, boredom is the kiss of death. And, if you’re not careful, disinterest and apathy at work can eventually bleed over into your personal life.

If taking on new responsibilities is an option, try that. But the simple fact is that some jobs restrict you to the exact same set of daily duties. If you find yourself regularly drifting into a glazed-over stupor while sitting at your desk, it’s probably time to get out.

3. All of Your Complaints and Arguments Have a Unifying Theme

Say, for example, your department is understaffed and it’s ruining your life. You’re working late hours, missing deadlines and delivering rushed, sub-par work. When you speak to your manager about the situation, you learn that there’s no plan to hire additional support. They’re aware of the issue and want you to “deal with it.”

This is the time you need to ask yourself “Can I adapt? Is this situation sustainable for me?” If the answer is “no,” it’s time to plan your exit strategy.

4. You’ve Lost Faith in the Leadership

Yes, we’ve all worked for a few yahoos. But there’s a difference between reporting to a crazy supervisor and dedicating your time and energy to a company with zero vision.

Look at your company’s leadership team and/or board of directors. If you can’t identify at least one strong leader that you respect and admire, that’s an issue.

5. Your “Case of the Mondays” Starts on Saturday Night

It’s normal for Mondays to drag a little. And lots of people get the “Sunday night blues.” But if the anticipation and dread of returning to work is creeping all the way back into your Saturday nights, that’s a red flag.

The truth is that we spend just as many, if not more, of our waking hours at work as we do at home. It’s not healthy to exist in a constant state of anxiety or duress. If your work is making you miserable, it’s time to make a change.

If it is indeed quitting time, follow John Stewart’s lead: recognize your need to move on and be honest with your employer. Then work with them to craft a transition plan that works for both of you.

Bonus points if you can sign off with a moment of Zen.

Are there any other telltale signs it’s time to leave a job?