This is the 7680th most frequent Russian word.
закончилось
"Ended" or "finished."
In this sentence, 'закончилось' refers to the milk being finished or consumed completely.
Молоко закончилось, нужно сходить в магазин.
The milk has run out, we need to go to the store.
Here, 'закончилось' metaphorically describes the end or exhaustion of my patience.
Сегодня закончилось моё терпение.
Today, my patience has run out.
In this context, 'закончилось' indicates the conclusion or cessation of a sunny day.