This is the 1308th most frequent Polish word.
min
"Min" in Polish means "facial expression" or "countenance."
In this sentence, 'minęło' means 'has passed', and it refers to the passage of time.
Minęło kilka dni od naszego ostatniego spotkania.
Several days have passed since our last meeting.
Here, 'mijającym' refers to 'passing', describing the ongoing year.
W mijającym roku wydarzyło się wiele ważnych rzeczy.
In the passing year, many important things happened.
In this case, 'minionego' refers to 'past', describing the concert as something that has already occurred.