Major restaurant chain operator Skylark Holdings Co. said Monday it will end around-the-clock operations by April due to a labor shortage and falling demand for such services.

The operator of restaurant chains such as Gusto and Jonathan’s will also shorten late night operating hours at some restaurants to focus manpower on lunch and dinner time services.

Skylark Holdings, which had 3,197 domestic outlets as of the end of December, said 566 outlets will reduce late night operating hours later this month, including 155 which are currently open 24 hours a day.

Skylark joins major convenience store operators in cutting back hours to address a labor crunch amid Japan’s graying population. The restaurant, retail, construction and logistics sectors are among those facing serious labor shortages.

Skylark started 24-hour operations at its restaurants in 1972 but started to reduce operating hours at some outlets in 2012.