“12.12: The Day,” a political drama revisiting a military-led coup that took place in 1979, has attracted 1.87 million moviegoers in the first week of release, according to Korean Film Council data on Monday.

The movie, which was released on Nov. 22, recorded the second-highest number of moviegoers in the opening week this year. “The Roundup: No Way Out” recorded 4.5 million admissions during its opening week in June.

On Saturday and Sunday, a total of 1.2 million moviegoers watched “12.12: The Day.”

Of the films released this month, “12.12: The Day” has attracted the largest number of moviegoers in the first week of release, surpassing “Inside Men” at 1.6 million in 2015.

The film covers nine hours on Dec. 12, 1979, during an attempted coup in Seoul. Although the film is based on a real-life event, the names of the characters have been altered to allow for a fictionalized plot, according to director Kim Seong-su. Kim has helmed various hit action noirs including “Beat” (1997), “City of the Rising Sun” (1999) and “Asura: The City of Madness” (2016).

Prolific actor Hwang Jung-min stars as Chun Doo-gwang, a core officer in the new military that instigates the coup attempt. Jung Woo-sung plays Lee Tae-shin, a commander who tries to stop Chun’s secret plan. Lee Seong-min and Park Hae-joon also appear as officers.

On the back of the film’s popularity, an online trend called “12.12: The Day Challenge” has gone viral, in which filmgoers share their heartbeat and stress level measured via smartwatch after watching the film.

“This challenge shows how angry, frustrated and heartbroken the audience feels about the plot, which is based on real events,” said an industry insider.

“12.12: The Day” is currently playing at local movie theaters.