What is the metric unit for time?

A second.

The metric unit for time is seconds

The metric unit (in SI) for time is the second (s).
The official definition of second is now (after CIPM): "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom; this definition refers to a caesium atom at rest at a temperature of 0 K".