The new Mother's Day must-have gift: an experience

America's biggest generation is giving Mother's Day a makeover. 

The traditional gift may have been a bouquet and fancy brunch, but millennial moms are the most likely age group to say they want a "gift of experience" to celebrate the holiday, according to a survey from the National Retail Federation. Spending on Mother's Day is projected to reach a record $23.6 billion by Sunday, the retail group said. 

Demands from millennials who want customized or "out of the box" gifts are prompting shifts in spending. While flowers remain a popular Mother's Day gift, fewer Americans say they'll order a bouquet or send a card this year than a decade ago, the NRF found. Instead, consumers are spending more on gift cards, consumer electronics and personalized services like a spa day for the moms in their families. 

"There is this changing mindset around how to celebrate Mother's Day and what moms might want and might not want," said Marie Chan, partner at brand strategy company Vivaldi. "It was this day where you could almost un-mom yourself. That's why you have these notions around, 'My husband will let me sleep in, my husband will give me the day off.''

She added, "I don't think that's what today's moms want. We don't want to be boxed in as a mom. Our world is much more expansive. We have different interests, different passions, and none of that is really changing because now we are a mom."

That bears out in research from the NRF. Thirty-six percent of Americans between 25 to 34 said they'd love to receive an experience for Mother's Day, the largest share of any demographic. The lowest share was for Americans over 65, with only 18 percent saying they'd like to receive such a gift. 

Mother's Day isn't unique to the phenomenon. Brick-and-mortar retailers are rethinking their services in a bid to keep customers walking through the door, given competition from online rivals and the preference of younger customers to spend money on experiences rather than things. Cosmetics chain Sephora, for instance, organizes special events and classes to attract customers, which has helped boost it to become the top specialty beauty retailer. 

Americans aren't skimping on Mother's Day, with the NRF finding the average expenditure this year will exceed $186 per person. Interestingly, millennials are shelling out the most, at $242 each. 

More than twenty-six percent of Americans say they'll give the gift of an experience to their mom this year, up from 22 percent a year ago. 

Chan noted, "Mother's Day is an excuse to check off one more passion, to do something that makes me happy."