班 is two pieces of jade 王 with a knife 刂 between them: dividing jade among nobles. From 'divide into groups' came every modern grouping — classes, teams, shifts, scheduled flights.
上班 clock in, 下班 clock out — the daily tide of Chinese cities. 班 is your class at school (三班, Class 3), your 航班 flight number, your 加班 overtime. 上班族 'the going-to-work tribe' is the Chinese word for commuters.
Jade split by a knife into groups — your CLASS, your SHIFT.
加班 'add-shift' is overtime, and 996 — 9am to 9pm, 6 days a week — became China's most argued-about work schedule. All powered by the character for splitting jade.