Fetching details from the dictionary...

attendance (at school); going to school
子供たちは毎朝八時に登校している。
The children go to school at 8 AM every morning.
大雪のため今日は登校が中止になった。
School attendance was canceled today due to heavy snow.
大雪の影響で登校時間を二時間遅らせると連絡が入った。
We received notice that school start time would be delayed by two hours due to heavy snow.