Making the jump from a day job to starting a company is a scary one. I don’t believe there’s a ton of real risk —after all, you’re probably highly employable (particularly if you’re a developer)— but it’s still a big leap. And often, people do it after they’ve saved up about a year’s worth of money so they know they can survive without regular income. Saving money in advance is good. Avoiding bankruptcy and abject poverty is also good.

But here’s the thing: when you give yourself a time limit, say a year, to “make it happen”, you often end up just filling up the time. And by “filling up the time” I mean you spend a year trying to get your startup to work, all the while not really adapting quickly enough or making the hard decisions you need to make … because, after all, you have a year.

I’ve seen a lot of people take this approach, and somehow, magically the time gets filled up and the progress just isn’t there. Now they’re out of savings and have to go back to a day job, leaving their startup in the lurch.

We tend to fill up the time we’re given, whether we need to or not.

If you ask someone to get something done by next Friday, generally, they’ll deliver next Friday, but not before. People don’t seem to value time enough, even though we understand it’s an extremely limited, non-replenishable resource. There’s always a reason for the time filling up, but it’s rarely justified.

Instead of filling up the time and exhausting your one year’s worth of savings, you should assume that you have no time at all. All the time. You shouldn’t be in a constant state of panic, but you can’t assume you’ll figure it out a few months from now and feel OK with that, simply because it’s within your window of opportunity. That window is closing all the time, faster than you realize. Don’t get caught giving yourself a set period of time to succeed and simply filling up the time, and not holding yourself to the highest standards of intellectual honesty and discipline needed to succeed.

When someone says to me, “I’ve got a year to figure this out,” I always think (and should say), “So you have a few weeks. Maybe a month or two. Three tops. At that point if you haven’t got something validated, you won’t have time to build a product, get traction and either raise capital or bootstrap with revenue.”

Don’t fill time.

Execute faster. Recognize you have no time. Be insanely honest with yourself and disciplined in your efforts. Pivot. Move on to something else if you have to. But don’t spend your time spending your time and spinning your wheels. In a year, your savings are gone, you’re broke and you haven’t made enough progress. It’s not the end of the world, but you would have been better off shifting ideas sooner, or saving some of your money, trying something new, getting another job and living to fight another day.