Why is it called a time series and not a time sequence?

Question

A sequence is defined as a function from ℕ to ℝ which assigns each natural number a real number a. A series is is defined as the sequence of partial sums of the sequence of real numbers (a). A time series is commonly defined as a sequence of values ordered in time. If that's the case, why is it called a "time series" and not a "time sequence?