ADDITIONAL SYSTEM INFORMATION :
Seems like all versions

A DESCRIPTION OF THE PROBLEM :
assertEquals(1,TimeUnit.MILLISECONDS.toSeconds(999));
Expected :1
Actual :0

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
TimeUnit.MILLISECONDS.toSeconds(999)


---------- BEGIN SOURCE ----------
import java.util.concurrent.TimeUnit;
import org.junit.jupiter.api.Test;


class AppTests {

@Test
void contextLoads() {
//default test case to show that spring is not broken
assertEquals(1,TimeUnit.MILLISECONDS.toSeconds(999));
}

}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
divide by 1000.0

FREQUENCY : always