The two-minute rule has its roots in GTD: If you can do it in less than two minutes, do it now (assuming you have no other, bigger priorities at the moment.) Over at the Buffer blog, James Clear adds another rule: When you start a new habit, divide your goals into two-minute bites so they're easy to do at any time.
We've mentioned the two0minute rule in the context of David Allen's Getting Things Done productivity method before, specifically when it comes to doing your weekly review. If you're looking over your list of to-dos or things to follow-up on, if you can do it in two minutes, jump on it and get it out of the way. If it will take longer than that -- either because you need to research it, talk to someone else, look something up, or produce something -- schedule it and get it into your productivity system so you can tackle it when you're ready.
James agrees, but takes it up a level and explains that if you're trying to build new habits and skills, if you make every step a two-minute chunk that can be done at any time, you'll be more likely to do it over and over again:
The 2-Minute Rule works for big goals as well as small goals because of the inertia of life. Once you start doing something, it's easier to continue doing it. I love the 2-Minute Rule because it embraces the idea that all sorts of good things happen once you get started.
... The 2-Minute Rule isn't about the results you achieve, but rather about the process of actually doing the work. The focus is on taking action and letting things flow from there.
You don't want to spend an hour on a "two minute" to-do only to find yourself behind on everything else because you didn't properly prioritise. Even so, the idea is sound. As we've said before, getting started is everything.
How to Stop Procrastinating by Using the 2 Minute Rule [The Buffer Blog]