No matter how much you love your job, you may not love it all the time. Folks with the most fulfilling of professions can still find themselves battling a case of the "Sunday Night Blues." And, from time to time, we may all feel a sense of disenchantment with our employer or our co-workers.

But how can you know when it's really time to go? Here's a hint: If more than half of the following statements ring true for you, get your resume ready and start connecting with new opportunities today.

1. You start to dread Monday as soon as you leave work on Friday.

2. It becomes more and more difficult to get up for work each day, and tardiness becomes a way of life.

3. You cannot muster enthusiasm for anything related to work -- other than your paycheck.

4. You spend most of your time complaining to colleagues or about your colleagues.

5. You act defensive and even hostile in company meetings when there's little cause for it.

6. You interact less and less with co-workers, shutting yourself away in your office and avoiding opportunities to socialize.

7. You've used up all your sick, personal, and vacation days -- and the year isn't even half over.

8. You're constantly putting off until tomorrow what you could (and should) do today. When you do actually commit to doing your work, you feel resentful.

9. You're bitter about the company's success or that of a co-worker.

10. You have no professional goals related to your job, and you have a hard time even making some up at your obligatory performance review.