Editor’s Note (December 21, 2017): Through to the end of the year, BBC Capital is bringing back some of your favourite stories from 2017.

Are you putting off a big project that you really should start today – perhaps holding out for the perfect possible time?

You could be on to something.

Most people decide to make changes in their lives around landmark dates. Mondays and the New Year are obvious choices for initiating a new, goal-oriented behaviour, such as getting started training for a marathon, getting out of debt or striving for a promotion.