Lusaka - A Zambian law that entitles women to take one day off work a month when they have their period is stirring increasingly fierce debate in a country reluctant to discuss sexual health.Discreetly called Mother's Day, the 2015 law - unique in Africa - enables women to be absent from work without notice or a doctor's note to help them cope with menstrual bleeding, pain and cramps."It helps me to manage my physiological needs (and) I think it's very important that I always endorse it," Shupe Luchembe, 36, a civil servant in the capital Lusaka and mother of three, told AFP."As a woman, it goes without saying that every month I need a special day away from the office to manage myself properly."In Zambia, a southern African country of 15.5 million people, discussing sex and personal health is largely taboo and often surrounded by secrecy and misunderstanding.Many parents prefer not to explain how their children were conceived and born, instead saying they were "brought from the hospital."'Progressive law' But two years ago, employment law was amended to grant all women - and not just mothers, despite its title - one day of menstrual leave each month after lobbying by campaigners."Mother's Day is a very progressive law," said Madube Siyauya, of the Non-Governmental Organisations' Co-ordinating Council ( NGOCC), an umbrella body of Zambian action groups."Some women have heavy flows, some of them have a lot of pain or vomiting."So it's a very important day that allows women to attend to their biological needs and continue their work without being susceptible to discrimination.""Zambia is envied because of this law," added Sara Longwe, also of the NGOCC, one of those that pushed for the law.'It is abused' But not everyone is a fan. While some Zambian women say the day off is widely abused, the law is also a popular subject for complaint among Zambian men."I have never taken Mother's Day in my life," Laura Miti, 46, head of the Alliance for Community Action, told AFP."I don't understand why others need it. It is abused. Whenever they have something they need to do, they would rather take the day off than taking leave."My sense is that giving half the workforce 12 days (off) extra per year is unproductive. It can't be productive, especially if you are working in the corporate world."Chiselwa Kawanda, 33, a government employee in Lusaka, agrees, saying the law was misguided."If I miss a day at work, it means I have to start all over the next day," she said, adding that, in any case: "You don't have periods for just one day."Zambia's approach is rare across the world, though Japan has had similar legislation since 1947 and Indonesia, Taiwan and South Korea have since followed suit.In Britain, Coexist, a small Bristol-based non-profit company, is experimenting with flexible hours for menstruating employees.'No evidence of low productivity' Despite the criticisms, the Zambian government says it stands by the legislation, which has no age limits so also applies to women after the menopause."Some women get sick, they are not able to concentrate on their work... so it was agreed that they can stay home without producing any certificate," Cecilia Mulindeti-Kamanga, of the labour ministry, told AFP."Of course there has been some complaints here and there but women go at different times. There is no documentary evidence of low productivity."Some Zambian women also allege that employers, particularly in the private sector, put pressure on female workers to not take their Mother's Day.Others point out that the vast majority of Zambian women cook, clean, bring up children and care for the elderly at home or toil in the fields with little time off of any description.The government has also introduced other programmes to support women. This year it started providing free sanitary pads to schoolgirls in rural areas to reduce absenteeism.Women in Zambia face widespread discrimination in education, law and employment, and the rates of child marriage and death during childbirth are high, especially in underdeveloped rural areas where most people live.