Jan. 24 [is] the “most depressing day of the year,” according to a U.K. psychologist.

Dr. Cliff Arnall's calculations show that misery peaks [on that day].

Arnall, who specializes in seasonal disorders at the University of Cardiff, Wales, created a formula that takes into account numerous feelings to devise peoples' lowest point.

The model is:

[W + (D-d)] x TQ
    M x NA

The equation is broken down into seven variables: (W) weather, (D) debt, (d) monthly salary, (T) time since Christmas, (Q) time since failed quit attempt, (M) low motivational levels and (NA) the need to take action.

Arnall found that, while days technically get longer after Dec. 21, cyclonic weather systems take hold in January, bringing low, dark clouds to Britain. Meanwhile, the majority of people break their healthy resolutions six to seven days into the new year, and even the hangers-on have fallen off the wagon, torn off the nicotine patches and eaten the fridge empty by the third week. Any residual dregs of holiday cheer and family fun have kicked the bucket by Jan. 24.

“Following the initial thrill of New Year's celebrations and changing over a new leaf, reality starts to sink in,” Arnall said. “The realization coincides with the dark clouds rolling in and the obligation to pay off Christmas credit card bills.”

Obviously, YMMV.