You could take a check for the smaller absolute delta of the value and the wanted value and return the object with the smaller one.
For getting a smaller value than the pivot add another check in front of the absolute check.
var data = [{ id: 1, time_in: 2 }, { id: 4, time_in: 10 }, { id: 4, time_in: 6 }, { id: 4, time_in: 25 }, { id: 4, time_in: 14 }],
pivot = 17,
result = data.reduce((a, b) =>
a.time_in <= pivot && Math.abs(a.time_in - pivot) < Math.abs(b.time_in - pivot)
? a
: b
);
console.log(result);