busy hour; busy period
Computing term for a period of high activity or peak load, such as network traffic or system usage.
The server's busy period is from 2 p.m. to 4 p.m.
最繁正時にはアクセスが集中する。
Access concentrates during the busy hour.
ピーク時 is a more common term for peak time in general contexts, while 最繁正時 is a technical computing term specifically for busy periods.
Compound of 最 (most), 繁 (busy/thriving), 正 (correct/regular), and 時 (time/hour). The exact derivation is uncertain; it appears to be a technical term formed within computing contexts.