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.

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