Interval Of Time, Time Interval, Period Of Time
Noun and Suffix
かん
気がついたら、五時間ぐらいねむっていました。
When I came to, I had been sleeping for almost five hours.
たのむから三分間だけだまっててくれないか？
For heaven's sake, can't you just be quiet for three minutes?
試験の中に、一定時間息を止めるというものがありました。一番難しかったのは、三時間息を止めるというものだったけれど、私はなんとかやり切りました。
The test involved having to hold my breath for fixed intervals of time. The most difficult one was for 3 hours, but I did it.
When you stick this onto the end of another word that talks about an interval of time in some way, you're indicating the amount of time that has gone past. For example, 二年間 is "two years." 一時間 is "one hour." Any amount of time + 〜間 will make it an "amount of time" instead of just a specific time.
The reading is the same as what you learned with the kanji. This should save you at least 二分間.