order of the day

order-of-the-day的词性：
n.（名词）

1. The business to be considered or done by a legislature or other body on a particular day. Often used in the plural.
议事日程，工作日程：议会或其他机构在特定的一天内考虑或完成的事务。 通常用复数形式

2. The characteristic or most significant aspect or activity:
特性：特征或最主要的方面或活动：

Volatility is the order of the day in the stock market.
上下浮动是股票市场整天的特点