Bei Bei did it again.

The National Zoo’s giant panda cub, who slept through his media debut in December and then snoozed through his public debut in January, demonstrated again on Saturday that he might benefit from an alarm clock.

When the time came for the 70-pound cub’s first birthday bash, he was a no-show — sprawled out on the cool concrete floor of his indoor pen while thousands baked in the heat outside for a chance to wish him well.

“Oh, no,” said Heiko Ramsey, who had planned a trip from Florida around the panda party, jokingly referring to Bei Bei as his “other baby” he came to see in the District — not just his son attending George Washington University.

After a while, however, Bei Bei’s mother, Mei Xiang, decided to devour her son’s frozen birthday “cake,” a 100-pound block of flavored ice packed with chunks of apples and sweet potatoes.

The National Zoo's panda cub Bei Bei decided to take a nap instead of celebrating his first birthday with a frozen cake. His Mom, Mei Xiang, enjoyed the 100-pound treat instead. (Reuters)

Only a handful of American and Chinese VIPs got to see Bei Bei frolic early Saturday, tasting his new favorite treat, honey, during the official celebration of his Aug. 22, 2015, birth.

And in the wacky political year of 2016, it also might have been the world’s first panda birthday party with geopolitical implications.

In an election year in which both Donald Trump and Hillary Clinton have forecast tougher times ahead for U.S.-China relations, the early morning event for Bei Bei took on an especially bilateral feel.

Standing in the zoo’s panda pen, Chinese Ambassador Cui Tiankai addressed more than 50 TV cameras from news outlets around the world. He called Bei Bei’s birth and healthy first year “fruit of collaboration between China and the United States and a strong symbol of our friendship.”

As if on cue, Mei Xiang soon sauntered up and began licking a bamboo stick holding a banner that read “Luck and Friendship.” The invited crowd of Chinese officials and zoo executives gushed as the elder panda’s move initiated a Chinese tradition of choosing a life symbol for the panda cub.

Leslie Wilkes nearly cried. The zoo volunteer said she saw truth behind the Chinese ambassador’s statement and hoped the message of cooperation wouldn’t be overlooked in the current political climate.

Mei Xiang chooses a symbol of luck and friendship. Bei Bei’s birthday celebration included a Chinese zhuazhou, a traditional ceremony, where several symbolic objects foretell something about a baby’s future by which is chosen. (Linda Davidson/The Washington Post)

“I don’t think people know how much we work together with the breeding center in China and how much collaboration there is behind the scenes to make this a success,” Wilkes said. “It’s really exciting.”

Dennis Kelly, director of the National Zoo, added a heaping dose of that sentiment later to a crush of reporters. He compared the United States and China to family, noting how Bei Bei seemed to need the support of his mother Saturday to feel comfortable joining in the ceremony.

Just after 8 a.m., it wasn’t clear that even the first wave of guests would get to see Bei Bei. After cautiously stepping into his outdoor area, the cub turned around and tried to climb a metal door, as if to return to where his mother was inside.

Bei Bei then waddled over to a pine tree and hid in the underbrush. After about 10 minutes, zookeepers let out Mei Xiang, who quickly followed her nose to where trainers had slathered honey onto three bamboo stems holding up banners with Chinese symbols.

First the 18-year-old mama bear approached the one with a Chinese knot, symbolizing friendship. It soon tumbled and the mother and cub licked the honey. The mama bear soon sent the other two, emblazoned with symbols for fertility and health, crashing to the ground and Bei Bei feasted on the honey.

At a news conference after the ceremony, Kelly was asked about the upcoming renegotiation with China in 2020 to keep pandas at the zoo. Kelly sought to tie it all together.

“I think Bei Bei told us one thing: Family is very important,” he said. “Americans, Chinese realize family is important and friendships are important, and it’s our friendship that will cause us to be successful for future generations.”

The first few hundred in line then got to see Bei Bei awake. But soon, the cub returned indoors and thousands who had waited to see him saw only the sleeping cub’s backside through a glass observation window.

Sai Tam said she wasn’t disappointed. She and her adult daughter awoke at 5 a.m. in New York. They drove a relative who uses a wheelchair and who had followed the cub’s development online to get a glimpse in person.

By the time the three made it to the front of the line, near noon, Bei Bei was long asleep.

“It is really meaningful to be here for the birthday, we feel like we know them. We watch them on the webcam — eat, sleep, eat” Tam said.

Edith Morris also said it was worth it. She had driven her four children, ages 3 to 10, from Columbia, Md. It was Bei Bei’s birth a year ago that prompted the family to become members of the zoo to get early access to the baby’s public events.

Morris said she makes the effort for the kids to celebrate the panda’s milestones at the zoo, knowing the animals’ time in the District is ultimately short. “We’re so sad about Bao Bao,” said her 10-year-old daughter, speaking of the first cub that grew up in the lens of a webcam. Bao Bao is expected to be returned to China next year when she turns 4.

The public celebration was supposed to culminate Saturday afternoon with the elaborate cake-eating display. Bao Bao awoke from a nap and had a cake with a big “3” on top. Her birthday is Tuesday.

But zookeepers couldn’t wake Bei Bei — despite even a practice run with the cub a day before.

“We did a dress rehearsal today and he did quite well,” Nicole MacCorkle, one of the zoo’s giant-panda keepers, said Friday. “I can’t imagine he’ll be a complete no-show.”

But on Saturday, that was the case. Volunteers yelled, “Bei Bei’s sleeping . . . keep moving,” as they tried to explain it was the wrong panda eating the cake.

Heiko Ramsey and his family didn’t budge for an hour, each wearing furry panda hats despite the afternoon sun.

After a while, Ramsey acknowledged that he probably wouldn’t see the cub: “Even if he doesn’t come back out, it was pretty cool to be here.”