Hyosung Group notified its staff in early December that it will apply collective vacation during the period so that the employees can make plans ahead of time. The conglomerate said the same system will be used throughout the year to link holidays with vacation days.

Samsung Electronics adopted "cultural innovations" last year for its workers to choose their vacations more freely.

"We encourage our workers to plan their yearly vacations and use the available days according to the plan," a company official said.

Chip plants, however, because they have to stay in operation year round, will keep their work shifts. SK hynix said it too is keeping its chip manufacturing lines in operation.

LG Group left the decisions up to its affiliates, with recommendations that vacations be taken on condition that necessary tasks are promptly handled. LG Display said it is adding May 8 as a recommended vacation day. This would extend the vacation period to 11 days by including May 9, designated as a temporary holiday because of the presidential election.

S-Oil is giving only May 4 as a collective vacation day, giving its workers a five-day vacation.

Hyundai Motor said it will run its manufacturing lines at full operation, except for holidays, and won't provide extra vacation time. (Yonhap)