"Time is our most valuable asset, yet we tend to waste it, kill it, and spend it rather than invest it." So says business author and speaker, Jim Rohn.

Whether you're looking for a new job or looking to get promoted in your current job, ask yourself this: What did you do with your time yesterday? Did you waste it, kill it, spend it, or invest it?

If you're not happy with your answer, read on to learn four ways to invest your time today, to get hired faster and get ahead on the job tomorrow.

1) First, track your time for one week

Before you can use your time better, you must know how you're spending your time now, so you can create a baseline to improve upon.

It's easy to do. Starting tomorrow, carry around a little notebook and keep track of how you spend your entire working day, in 15-minute increments. Attorneys, accountants and other service professionals who bill by the hour do this every day, so don't say it's too much bother!

This is one of the most valuable things you will ever do in your career -- I guarantee it.

Track your time for just one day and there's a 100% chance you will be surprised at how you spend it. Do this for one week and it will be like pulling back the curtain on the Wizard of Oz -- a shocking revelation.

2) Check email twice a day, at most

Once you track your time and know how you spend it, let me predict one way to get more done each day: spend less time on email.

Paradoxical? No.

After I first tracked my time in 2004, I found I was spending 6 hours a week reading and responding to email. That's 24 hours a month -- three full working days. Too much.

So I resolved to check email once an hour instead of every 15 minutes ... or every time I got bored. Yes, withdrawal was painful (there's no methadone equivalent for this). But my productivity went up.

Then I got it down to four times a day. Now, after a year of cutting back, I check email just twice a day. As a result, I spend less than three hours a week on email -- a 50% productivity gain. What could you do with an extra 150 working hours a year? That's my happy problem these days.

3) Turn off -- no, get rid of -- instant messaging

I'm sure there's a perfectly good reason to put instant messaging on your computer and be open to interruptions at any time, from anyone, about anything. I just haven't found that reason.

If you're out of high school and have to earn a living, I can't see any point in letting some electronic gremlin sit on your shoulder and shout, "Hey, instant message!" into your ear every two minutes.

If anyone can IM you at any time, what does that say about the value you put on your time? And how much time do you waste each day as you mentally shift gears to respond to IM, get back to work, respond to IM, get back to work, etc. Nuts to that.

I'll wager $100 there's not a single Fortune 500 CEO with IM. They have better things to do with their time. So do you.

4) Avoid "Got a minute?" meetings

The next time a co-worker walks into your cubicle (or a friend calls to chat during your job search) and asks, "Got a minute?" say, "Yes, actually, just one minute and then I have to finish something. I'm on a deadline."

(The word "deadline" concentrates a conversation wonderfully.)

Then, look at your watch and give that person ... 60 seconds. If they need more time to talk, ask to schedule a short meeting later, when it's convenient for you. Then, get back to what you were doing.

It's amazing how many 15-minute gabfests can be cut to 60 seconds or less when you give someone a one-minute time limit.

Your Takeaway Lesson -- These four tips (none of which they teach in school, by the way) will help you get hired faster and get ahead on the job by getting more done each day.

There's a reason why Bill Gates, Warren Buffett and Oprah are at the top of their professions: they get a great deal done during the same 24 hours that you and I get every day.

Starting today, start investing your time wisely. You'll do great things when you do.