Date FunctionsAdvanced
Capstone: schedule the install dates
Working days, month ends and the day of the week.
Task:
Each install needs a date the crew can actually work. In column D give the date that falls the stated number of working days after the start, in column E the last day of the start month for the billing cut-off, and in column F which weekday the job starts on as a number.
The data in this exercise
This is the grid you start with. Cell references in the task — B6, C2 — point at the row numbers and column letters below.
| A | B | C | D | E | F | |
|---|---|---|---|---|---|---|
| 1 | Job | Start | Lead (working days) | Install | Billing cut-off | Start weekday |
| 2 | J-1 | 3/2/2026 | 10 | |||
| 3 | J-2 | 3/16/2026 | 5 |
What this exercise teachesMay contain the answer
Adding ten to a date gives you a Saturday half the time, which is why WORKDAY exists. EOMONTH is the reliable way to reach a month end without caring whether the month has 28, 30 or 31 days — and February is precisely where hand-rolled date maths falls over.