在会计上有时点数和时期数，时点数表示的是月末或某一时间的账面月额，时期数是一定时期内的累计数，这两个词英文该怎样译？

Amount at a point of time, Amount over a period of time
时点数 时期数
"The balance sheet, also called the statement of financial position, summarizes the resources, obligations, and residual ownership interests in an entity at a point in time.平衡表，亦称作财务状况表，是企业在某时点上对资财，债务和所剩所有权利润的总结。

Balance Sheet is prepared on basis of specific time point, such as on Sepet.30,2009.
Profit and Loss Statement is made on basis of specific period of time, such as in Sepet,2009.

The profit and loss statement shows transactions over a given period of time (usually quarterly or annually), whereas the balance sheet gives a snapshot holdings on a specific date.