Why the assembly lines never sleep

The reason is structural. Semiconductor fabs in particular cannot simply be idled and restarted: stopping production lines is costly and time-consuming, and output must be sustained to meet customer orders. Plants run under continuous operation schedules that leave no room for a national holiday, with workers rotating through holiday shifts rather than shutting the lines down.

Holiday shifts at Samsung, SK and LG

Samsung, SK and LG facilities accordingly keep full 24-hour operation during Chuseok, maintaining production of semiconductors, displays, and electronics for global markets. Only maintenance, repairs, or scheduled upkeep can briefly halt equipment — otherwise the production rhythm continues as on any other day.

The overall assessment of the claim: Mostly True.