LONDON — Having a bad day? Well, no wonder. According to one scientist, today is the gloomiest day of 2006.

Cliff Arnall, a health psychologist at the University of Cardiff in Wales, has devised a formula that combines personal and seasonal factors to calculate that Jan. 23 is the year's emotional low point.

Arnall said January is a time when people are simply working and don't have a lot of events, parties or holidays to look forward to.

People are struggling to cope not only with the bleak weather but also with the debts they amassed by spending too much over the holidays.

It's also a time when people are starting to feel like failures because they've broken their resolutions so shortly after making them.

On paper, the formula looks like this:

1/8W + (D-d) 3/8 x TQ

----------------------

M x NA

The variables are (W)eather, (D)ebt, (d) or monthly salary, (T)ime since Christmas, time since failure to (Q)uit a bad habit, low (M)otivational levels and (NA), the need to take action.

Arnall said his formula holds true for the United States as well as Britain, except perhaps in places such as Texas, Florida or California, where better weather could help to lift the day's mood.

But Arnall said there are ways to beat the late-January blues. "I also advise people to do the unusual every January," he said. "Go for a walk in the woods or just get out and about."

Arnall said groups of friends or even office mates could throw parties to celebrate the 23rd, since being around people you like can be a great way to boost your spirits. People also could resolve to make a budget for their holiday spending next December.

Leslie Godwin, a Los Angeles-based author and life transition coach, agreed that January is a tough time of the year. She encouraged people to try to exercise, whether the weather's bad or not.

"Exercise releases hormones that give us a sense of well-being, and it should be seen as an antidote to feeling down or blue," she said.

Godwin, who emphasized that it generally takes three weeks to create a habit, said the best exercise is any kind you are likely do at least five days a week.

"If you start exercising around New Year's, then you will have formed a positive new habit by the end of the month," she said.

Arnall adds that all is not gloom and doom. The good news? It's only six months until what Arnall figures will be the happiest day of 2006 — June 23.

"In June there is a lot more of an emphasis on nature, with plenty of flowers and trees in full bloom . . . ," he said. "People are experiencing positive memories of their childhood summers and they are looking forward to taking their holidays. "All this happens in June, so that it's usually a very good month."

It might be expected that a formula for unhappiness would be created in Britain, because the British generally are a glummer lot than Americans. According to Ruut Veenhoven, a sociologist at Erasmus University Rotterdam and creator of a new "life satisfaction index," Britain is ranked below 20 other nations, including far poorer countries like Ghana, Mexico and Uruguay, when it comes to happiness.

One happiness index found Malta to be the happiest country, with the U.S. ranking 13th alongside Guatemala, Norway, and Uruguay.

In general, researchers found that marriage — not money — makes a greater impact on a person's happiness and especially on how long they live.