Day Payable Outstanding指的是“应付账款变现天数”，又称应付账款周转天数，指公司支付其应付账款平均所需天数，用于衡量公司需多长时间付清供应商的欠款，属于公司经营能力分析范畴。Days payable outstanding (DPO) is a financial ratio that indicates the average time (in days) that a company takes to pay its bills and invoices to its trade creditors, which may include suppliers, vendors, or financiers. The ratio is typically calculated on a quarterly or annual basis, and indicates how well the company’s cash outflows are being managed. (Investopedia)

应付账款变现天数的计算公式(Formula for Days Payable Outstanding) 为：

DPO=Accounts Payable应付账款 × Number of Days天数/ COGS销售的物料成本

Where:

COGS=Cost of Goods Sold销售的物料成本

=Beginning Inventory期初存货 + Purchases采购- Ending Inventory期末存货

一般来说，DPO高的公司可以延期付款，并使用可用的现金进行短期投资，增加其流动资本和自由现金流，但有时候DPO高也可能会被视为现金短缺及无力付款的信号。

Days Sales Outstanding企业销售变现天数，表示每笔应收账款的平均回收天数，即把赊销转化为现金所需要的时间。对于信用管理部门，DSO几乎是衡量其工作效果的重要指标,可以从侧面反映企业应收账款管理的效率高低。Days sales outstanding (DSO) is a measure of the average number of days that it takes a company to collect payment after a sale has been made. DSO is often determined on a monthly, quarterly or annual basis, and can be calculated by dividing the amount of accounts receivable during a given period by the total value of credit sales during the same period, and multiplying the result by the number of days in the period measured. (Investopedia)

企业销售变现天数的计算公式（Formula for Days Sales Outstanding）为：

DSO企业销售变现天数=Accounts Receivable应收账款/Total Credit Sales总销售额×Number of Days天数

一般来说，DSO在45天以内的则被视为低DSO，然而，DSO的高低常常更取决于具体的商业类型和架构。