In Greece, it is believed couples shouldnt get married during a leap year. It is said to bring bad luck to the family.

London - If you're not sure what day it is today, you are not alone – Britons are confused about the day of the week four times out of ten.

Mundane Tuesdays, Wednesdays and Thursdays are particularly forgettable, according to Lincoln and York University researchers.

They said we associate Fridays with fun and Mondays with misery so the days that fall in between struggle to stand out.

The study also revealed that Fridays are perceived as being more enjoyable than Saturdays, with Sundays being especially glum.

In one part of the study, volunteers were simply asked which day it was – and timed while they came up with their answer. Mondays and Fridays came to mind twice as quickly as Wednesdays.

The research also showed how often we get the day wrong. Overall, almost 40 percent of those quizzed were a day out and most of these mistakes occurred in the middle of the week, the journal PLOS ONE reports.

Public holiday weeks proved particularly tricky, with the extra day off work causing such confusion that more volunteers got the day of the week wrong than got it right.

The study also revealed that we associate certain days with certain words.

As the first day of the working week, Mondays bring to mind things that are “hectic” and “boring”, as well as sleepiness and tiredness.

In contrast, Fridays are associated with fun, friends, drinking, parties and freedom.

Tuesdays, Wednesdays and Thursdays do not have such a strong identity.

Researcher Dr David Ellis said: “The seven-day weekly cycle is repeated for all of us from birth, and we believe this results in each day of the week acquiring its own character. Our research implies that time cycles can shape cognition even when they are socially constructed.

“The holiday effect implies that apparent weekday is not determined solely by the seven-day period of the weekly cycle: transitions between the working week and weekend also play a role.”

The popularity of Mondays and Fridays with songwriters may also play a part. They feature in numerous songs from Manic Monday by the Bangles to Friday I'm in Love by The Cure - but Tuesdays, Wednesdays and Thursdays are less musical.

Co-author Dr Rob Jenkins, from the University of York, said: “One reason behind midweek days evoking fewer associations than other days could be down to how infrequently they occur in natural language, thus providing fewer opportunities for associations to form.

“For example we have an abundance of pop songs which make use of Mondays and Fridays, while the midweek days are rarely used.”