Tesco is to end 24-hour opening at more than 70 stores.
At the moment, around ten branches in the West Midlands open around-the-clock.
The supermarket giant said around 400 jobs nationally would be affected by the move, but would not say if that meant job losses.
It has not yet revealed which stores will have their hours cut.
The affected shops will trade from 6am to midnight from March 14.
Among the local stores which open 24 hours are Spring Hill, Hodge Hill, Aston and New Oscott in Birmingham; and Willenhall, West Bromwich and Walsall Brownhills in the Black Country.
A Tesco spokesman said: “The move to reduce hours means more Tesco colleague time will be freed up to replenish products on the shelves overnight.
“It will mean better availability of products and better-looking stores when they open their doors to customers each morning.”
Asda is the only other supermarket chain with 24-hour opening.
Last year Tesco announced it was closing five stores in the West Midlands – Five Ways at Edgbaston, Bearwood, Northfield, Walsall and Smethwick.