A propaganda image published over the 33rd April Spring Friendship Art Festival is seen in this file photo carried by North Korea's official Korean Central News Agency, April 2. Yonhap

North Korea has been ramping up a festive mood to celebrate the upcoming 112th birthday of late founder Kim Il-sung, but its state media has been recently referring to it as "the April holiday" instead of what's commonly called the Day of Sun.

Kim died of heart failure in 1994 at age 82, opening the way for his son, Kim Jong-il, to take over in communism's first hereditary succession of power.

Despite the senior Kim's death, his birthday, April 15, is revered as the Day of Sun and is celebrated as one of the communist country's most important national holidays along with his late son's birthday in February.

But the Korean Central News Agency on Tuesday carried a report that said about 1,200 participants held performances at a schoolchildren's art festival the previous day on the occasion of "the significant April holiday."

The North has also renamed the annual cooking festival that has been held every April to mark Kim's birthday, dropping the term Day of Sun from its original name.

Seoul's unification ministry said it is "unusual" that North Korean state media has been referring to Kim's birthday as "the April holiday" or the "spring holiday in April" in recent weeks.

"I think it will be appropriate to assess (what that means) after comprehensively looking at media reports coming out until April 15," a ministry official told reporters, when asked if North Korea is viewing Kim's birthday as less important than before.

North Korea holds a photo exhibition marking the 112th birthday of late founder Kim Il-sung in Pyongyang, April 8. Yonhap

North Korea has held cultural events or art festivals ahead of the anniversaries of Kim Il-sung and Kim Jong-il's births in an effort to idolize them and justify the hereditary power succession of the "Paektu bloodline."

"If the North does not continue to use the term Day of Sun, (Kim Jong-un) may intend to minimize his grandfather's feats while maintaining the legitimacy of the Paektu bloodline," Yang Moo-jin, president of the University of North Korean Studies, said, referring to North Korea's royal bloodline.

The North claims Mount Paektu, the highest peak on the Korean Peninsula and located on the Sino-North Korean border, is the sacred birthplace of Kim Jong-il, though historians and foreign officials have said he was born in Russia.

Kim Il-sung is known as the role model of the North's incumbent leader. But at a year-end party meeting, Kim Jong-un scrapped a decadeslong policy of seeking unification with South Korea, a legacy of his grandfather, and defined inter-Korean ties as those between "two states hostile to each other."

But it still remains to be seen whether the North would remove the term Day of Sun completely from its state media reports.

In February, the Rodong Sinmun, the North's main newspaper, carried reports referring to the Day of Sun and the Day of the Shining Star, which is Kim Jong-il's birthday on Feb. 16.

The festival comes amid lingering tensions over a series of missile launches by North Korea in recent months in violation of U.N. Security Council resolutions.

This year, North Korea is not likely to hold a large-scale military parade to mark Kim's birthday, as the country has usually held such a military event on anniversaries whose final numbers end in a five or zero.

The South Korean military is closely monitoring Pyongyang's possible preparations for provocations on the occasion of Kim's birthday and the founding anniversary of the Korean People's Revolutionary Army on April 25. (Yonhap)

（作者：汽车电瓶）