Unlike here in the states, where moms are given a special day in May, the UK celebrates Mother’s Day on the fourth Sunday in the month of Lent to honor the Virgin Mary. Since the days of Lent change every year, Mother’s Day is not a fixed date in the UK, and this leads to forgetfulness regarding the holiday. This year it falls on Sunday, March 18th, which just happens to be this weekend. Twitter users have been helpfully reminding each other, lest they be subject to their mum’s guilt wrath.

The day has deep roots, going back to at least the 1600’s. In those days, the poor used to send their children to work as domestic servants in the homes of the wealthy. Once a year, these children were given leave for a day to visit their Mother Church as well as their own mother. The day coincided with the middle Sunday during the fasting period of Lent, and since then it has become a tradition to honor one’s mother on that day. Children would present their mothers with flowers and the traditional fasting rules of Lent were relaxed a bit, prompting the nickname “Pudding Pie Day”.

Popular gifts may change from year to year, but flowers are always in demand for the holiday and reportedly ranked highest last year, even over cards. For those last-minute shoppers, there are sites which feature free greeting cards which can be sent via email to mom as well as some that offer free delivery of personalized gifts.

Of course, these days companies are using social media tools to help make sales. Twitter was buzzing today with posts about Mother’s Day UK, from promos and giveaways–which range from theater tickets to chocolate baskets–to gift ideas. It seems everyone is trying to make sure that moms are not forgotten this weekend.