Why Some 30-Minute Appointments Seem Longer than Others

In another, they asked 600 people to schedule activities—some they’d want to savor and others they’d want to complete as quickly as possible—during various time slots. As expected, participants scheduled the more desirable events for periods that crossed more hour boundaries (and, thus, felt longer), and arranged the less desirable activities into time slots that crossed fewer hour boundaries.

Donnelly, Compiani, and Evers also explored whether this behavior could be explained by left-digit bias, a phenomenon typically discussed in the context of pricing that occurs when consumers focus disproportionately on the leftmost digit—the reason retailers price items at $3.99 rather than $4. Is it this cognitive tendency that makes 2–2:45 p.m. feel shorter than 2:30–3:15 p.m.?

To find out, the researchers recruited participants in the United Kingdom, where dates are written as day-month-year—instead of month-day-year, as in the United States—and asked them to rate how long several date ranges felt. Though the boundary-crossing digit—the month—was in the middle, and not on the left, participants said dates that spanned more months felt longer, and vice versa. The results suggest consumers are influenced “not by the leftmost digit but rather by the most differentiating unit,” they write.

How do these perceptions of time affect spending decisions? The researchers looked to rideshare data from Chicago to find out. Starting with data on more than 3 million rideshare trips taken between November 2018 and December 2019, they created a model to understand how temporal boundaries might influence a customer’s choice between an independent ride and a shared ride, with the latter being a cheaper (but longer) option. After factoring in consumers’ general preference for rides that are both shorter and less expensive, they find that riders were substantially less likely to choose a shared ride when its estimated arrival time would cross into a new hour and the independent ride would not (compared with when both rides were estimated to arrive before or after the next hour). They further calculate that rideshare companies could use this insight to adjust their pricing strategies to capture an extra $0.30 of revenue per ride.

Apart from rideshare services, marketers in a variety of industries might take advantage of consumers’ variable perceptions of time to sway purchasing decisions. To keep customers happy, companies such as Grubhub and DoorDash might want to minimize the number of orders with wait times that cross into a new hour, for instance. Airlines may want to strategically adjust layovers so they span as few time boundaries as possible. Similarly, dentist offices—which many people dread visiting—may want to offer appointments that start and end within the same hour.

“Companies may want to pay special attention to situations where times have the potential to cross a new hour or month,” says Donnelly.