Where the Moving-Average Window Sits

A café counts its customers on six consecutive days:

The analyst uses the trailing $k$-period simple moving average

$MA(t) = \frac{y(t) + y(t-1) + \cdots + y(t-k+1)}{k}$

What is the value of the 4-day moving average on Saturday (a window of four days that ends on Saturday and includes it)?