Millions of people living in North Korea will be expected to join forces to celebrate the birthday of the man who leads the country, Kim Jong-un.
Still, little is known about the elusive leader, including exactly when he was born.
Just days before the occasion was marked, the regime made an as-yet unproven claim that it had successfully carried out its first underground hydrogen bomb test.
That triggered a global outcry and fears that the state, which has few allies, had acquired a more advanced nuclear capability than previously known.