As Marilyn Monroe's 1955 movie The Seven Year Itch suggested, after seven years, marriages have a high risk of coming to an end.

That duration is even shorter for China's post-1980 generation, if two court reports are to be believed.

A report released by Shanghai's Huangpu District People's Court ahead of Singles' Day on Monday said the length of marriages it legally put asunder averaged only three years and nine months.

The court reviewed more than 700 marriages, in which one or both spouses were born in the 1980s, that ended in its divorce tribunal in the past three years.

The Lucheng District People's Court in Wenzhou, Zhejiang province, confirmed the trend.

Of the divorces handled by the court from January to August, 98 marriages of the post-1980 generation lasted an average of three years. One-fifth of them did not last even a year.

Divorce has been increasing at an annual rate of around 8 percent in China over the past 10 years, according to the Ministry of Civil Affairs. Moreover, the percentage of divorced couples aged between 22 and 35 is increasing, and "lightning divorces" within one year of tying the knot are no longer rare.

Some hotels and restaurants said they sometimes see couples cancel wedding celebration reservations because they decided to divorce.

"We have had such a situation twice this year," said Chen Wei, a manager at Jingpuhui, a high-end restaurant in Shanghai's Changning district. "The loss of the down payment of around 30,000 yuan ($4,900) didn't change their minds."

Chen said newlyweds usually make reservations for their reception a year ahead.

Not knowing each other well enough before marriage, and lacking tolerance, are among the main reasons young couples choose to part, the Huangpu court report said.

The report said half of the young people surveyed married within one year after they began dating, but eight couples tied the knot within one month.

"Some couples lacked understanding of each other and some didn't even know the spouse had a child or a history of mental problems," said Tang Zhengming, a spokesman for the court.

Experts said lower divorce rates in the past did not indicate higher marital satisfaction among past generations, but that people were more tolerant and patient in dealing with family problems.

"However, the post-1980 generation grew up being spoiled by parents and grandparents, which makes them more self-centered, and their conflicts can escalate from something trivial, such as how to share chores," said Shu Xin, head of the China Marriage and Family Counseling Center.

Materialism also negatively impacts young people's marriages.

"More marriages are becoming utilitarian with more people jumping into a marriage for the sake of housing, luxuries or a registered permanent residence in a big city," said Zhou Xiaopeng, an expert at Baihe, a popular matchmaking website. "These marriages, based on material issues rather than personality and mutual attachment, are fragile."

Divorce is not the only solution to differences between a couple, and "imprudent divorce may cause their children to adopt a bad attitude toward love and marriage", Shu said.