Follow the calculation
A service periodThe interval represented by the billed service quantity.
Example: April’s 30 days are separate from the May issue date. describes the interval being charged. The issue date says when the bill was prepared; the due date says when payment is requested.
They answer different questions. For calculations in this course, use the stated billing-day count rather than guessing whether printed endpoints are inclusive.
If your own bill’s day count does not reconcile with its dates, record the discrepancy and ask the retailer how the period was defined. A late-issued bill can cover an earlier interval, so filing only by issue month can confuse comparisons.
Apply it
Synthetic bill A covers 1–30 April, states 30 billing days, is issued 4 May and is due 24 May. A second bill covers 1–31 May and states 31 days.
Record the service interval and day count for bill A, then choose the day count used for its daily consumption calculation.
Response location: Identity and period, practice 3. Attempt this before opening the model.
Solution and explanation
Bill A belongs to the April service interval and uses 30 days. Neither 4 May nor 24 May determines its daily-use denominator.
The quantity relates to the service interval, while issue and due dates govern document and payment handling. Keep all three dates, but use each for its own purpose.
Check your work: Use 30 days and label it service days, not days until payment.