There are no longer any base units as of the 2019 SI redefinition, but prior to that the second was the base unit for time. Hour and minute we’re defined based on that. And now even though a second isn’t a base unit, hour and minute are still defined based on the second, not the other way around. It’s been that way for several decades now. Maybe you’re thinking of some no-longer-used system.
There are no longer any base units as of the 2019 SI redefinition, but prior to that the second was the base unit for time. Hour and minute we’re defined based on that. And now even though a second isn’t a base unit, hour and minute are still defined based on the second, not the other way around. It’s been that way for several decades now. Maybe you’re thinking of some no-longer-used system.