Seoul, South Korea(CNN) April 15 is North Korea's most important holiday, the Day of the Sun.
It celebrates the birthday of the country's founding father, Kim Il Sung, and has in the past been marked with events like satellite launches and massive military parades. The North Korean calendar even begins on April 15 and years are measured from the date of Kim's birth.
But this year, celebrations were more subdued and appear to have come and gone without a public appearance by leader Kim Jong Un, which is unusual.
North Korean state media did not report his presence at Day of the Sun festivities on Wednesday. The country's state-run news agency, KCNA, reported that "senior officials" made the customary visit to Pyongyang's Kumsusan Palace of the Sun, the mausoleum where the bodies of Kim Il Sung and his successor and son, Kim Jong Il, are both on display.
Experts are unsure of what to make of the youngest Kim's purported absence. North Korea has no free press and is often a black hole when it comes to the country's leadership. Analysts are heavily reliant on scanning state media dispatches and watching propaganda videos with Talmudic precision, reading the tea leaves for any semblance of a clue.
Duyeon Kim, a senior adviser for the International Crisis Group on Northeast Asia and nuclear policy, said it was "unprecedented for him to skip paying his respects."
"Ever since he took power, he always showed up for these most important days for North Korea. It's so far unclear if he paid tribute by himself before the others," she said.
Absences from important celebrations in the past have sometimes proved to portend major developments. They've also turned out to be nothing.
Kim Jong Il's absence from a parade celebrating North Korea's 60th anniversary in 2008 was followed by rumblings that he was in poor health. It was later revealed he had a stroke, after which his health continued to decline until his death in 2011.
Kim Jong Un disappeared from the public eye for more than a month in 2014, which also prompted speculation about his health. He returned sporting a cane, and days later South Korean intelligence said that he had a cyst removed from his ankle.
"It's easy to be wrong on this one," said John Delury, a professor of international relations at Yonsei University in Seoul. "Most of the time we get this wrong, when an appearance is expected and doesn't happen. It's really hard sometimes for a while to figure out what caused it."
At first glance, the coronavirus pandemic could be a culprit.
Though North Korea has not reported any cases within its borders -- a claim public health experts say is unlikely -- Pyongyang has taken the pandemic very seriously. The country quickly closed its borders to tourists and quarantined foreign diplomats, who eventually left. State media included several warnings and reports about the importance of proper hygiene in February, while also outlining steps the government was taking to combat the virus.
North Korean state media released a photograph it claims showing Kim chairing a meeting on public health efforts less than a week ago, in which they agreed to intensify "nationwide emergency anti-epidemic services," KCNA reported Sunday.
Cheong Seong-chang, a director of the Sejong Institute in Seoul, said it was unusual that Kim chaired that meeting but may have then skipped out on an important opportunity to honor his father and grandfather.
He said it's possible that Kim may have had a temporary personal or health issue, but that "it is difficult to judge how serious the situation is."
However, limiting the celebrations organized for Day of the Sun might have been a prudent move to emphasize social distancing and prevent community spreading.
Keeping Kim away from the celebration also could have been a way to protect the young leader from potential exposure to the virus.
"This is a leader whose kind of trademark was hugging his people a lot. You think of the images we have of condolence domestically, he's out there pressing the flesh. There's people crying next to him quite a bit -- much, much more than his father. And that's a huge danger if you're at all worried about the virus," Delury said.
"I think we have to include the possibility that this is related to their process to make sure he stays safe."