Most people spend every second of their workday trying to keep up with their calendars and to-do lists — attending meetings, responding to emails, racing to meet deadlines.

This makes it difficult to set aside time to explore ideas that interest us or learn new skills. And during a time when it's impossible to predict how our jobs and industries will evolve, expanding our expertise is what gives us a competitive edge in the long-run.

How can we ensure we make the time to stay ahead?

Enter: Google's "20% time" rule, a concept made popular when Google went public in 2004.

"We encourage our employees, in addition to their regular projects, to spend 20% of their time working on what they think will most benefit Google," founders Sergey Brin and Larry Page wrote in their IPO letter. "This empowers them to be more creative and innovative. Many of our significant advances [like AdSense and Google News] have happened in this manner."

Sure, it's easier said than done, but no one is going to hand you development opportunities on a platter; you need to seek them out proactively.

Here's how:

1. Clearly identify what you want to learn

The key here is to be as specific as possible about what skill you want to build. So instead of taking 10 courses on 10 different topics, develop mastery in just one.

You'll see faster improvement over time, which will motivate you to continue. And genuine expertise — for example, in writing great sales copy or programing in a new computer language — may ultimately boost your value to your employer or lead to a side income stream.

2. Win — even if you lose

This is the ultimate way to make sure your 20% time doesn't go to waste. Figure out the minimum benefit you'll get out of a given situation or opportunity, even if nothing else breaks your way.

It might be exposure to a new industry, making connections in a different region, or practicing valuable skills like public speaking and clear communication.

If the minimal outcome alone sounds intriguing, then the project is likely a good bet.

3. Be flexible and committed

Protecting your 20% time is like maintaining a diet: It's good to be disciplined, but sometimes you need to bend the rules and be flexible.

Client emergencies or impromptu staff meetings may prevent you from spending the time you've allocated in your calendar, and that's okay — as long as you make a point to reschedule it and keep that commitment.

The point isn't that you have to do your 20% time every Thursday afternoon; the point is to do it, period.

4. Look for ways to make it fun

It takes effort guard your 20% time, and it's a lot harder to maintain that willpower if all you're doing is endless homework and rigorous training sessions.

You may need a hardcore dose of that willpower periodically because in any discipline, there are some challenging elements you'll have to master. But if difficult tasks are the only thing you do, you may grow bored or frustrated and want to quit.

There are plenty of ways to make your 20% time enjoyable, such as listening to audiobooks while taking a walk, having informational interviews with colleagues over a nice lunch or taking a course with a friend. 

5. Think in decades

Just like with an investment in the stock market, when you invest time in your 20% projects, the power of compound interest is dramatic. What at first seems small and meaningless can enable you to put massive distance between you and your competitors. 

The gift of the 20% time, especially when we think in decades, is that even if we ultimately change plans or decide on a different course, the small steps we take now compound over time and give us more options in the future.

Dorie Clark is a marketing strategist and lecturer at Duke University's Fuqua School of Business. She is the author of "The Long Game: How to Be a Long-Term Thinker in a Short-Term World" and has been featured in Harvard Business Review, The New York Times and Fast Company. Follow her on Twitter @dorieclark.

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