You manage a task tracker with start dates, due dates and completed dates. Your manager asks which tasks are overdue, how many days remain, and which month each task belongs to. Date Functions make this automatic.

Use TODAY for dynamic aging

=TODAY() returns the current date. This is useful for reports that should update automatically every day, such as overdue tasks, invoice aging or days until due date.

Task timeline example

TaskDue DateDays Until DueStatus
Validate customer data08-Jul-2026=DueDate-TODAY()Overdue / Open
Prepare client tracker20-Jul-2026=DueDate-TODAY()Open
Simple rule: Use TODAY when the result should change automatically based on the current date.

Extract month, year and day name

Date parts help you group tasks, sales, invoices or tickets by reporting period.

=TODAY()   =MONTH(A2)   =YEAR(A2)   =TEXT(A2,"dddd")
MONTHReporting month
YEARReporting year
TEXTReadable day name

Working days and month-end dates

NETWORKDAYS counts working days between two dates. WORKDAY calculates a date after a number of working days. EOMONTH returns the month-end date.

NETWORKDAYS=NETWORKDAYS(StartDate,EndDate)
Counts working days between dates.
WORKDAY=WORKDAY(StartDate,5)
Finds date after 5 working days.
EOMONTH=EOMONTH(Date,0)
Returns month-end date.
DATEDIF=DATEDIF(StartDate,EndDate,"d")
Calculates date difference.
💡
Professional habit: Store dates as real Excel dates, not text. Text dates may look correct but can break formulas and sorting.
⚠️
Common mistake: Typing dates in inconsistent formats. Use a clear date format like dd-mmm-yyyy or yyyy-mm-dd.

Interview question

Question: How would you identify overdue tasks in Excel?

Answer: Compare Due Date with TODAY using a formula like =IF(DueDate<TODAY(),"Overdue","Open"). For completed tasks, also compare Completed Date with Due Date to check if it was completed late.

🧪 Practice Lab

Build a task aging and timeline report

Download one ZIP file containing the practice workbook, challenge workbook, solution workbook, formula cheat sheet, quiz and answer key.

📦 Download Lesson 22 ResourcesWorks as a standalone file and after website deployment

Mini assignment

  1. Use MONTH and YEAR to extract reporting period.
  2. Use TEXT to show day name.
  3. Calculate task duration using date subtraction.
  4. Use TODAY to calculate days until due.
  5. Use IF to mark overdue tasks.
  6. Create a readable timeline label using TEXT.

Quick quiz

  1. Which function returns today's date?
  2. Which function extracts month?
  3. Which function counts working days?
  4. What does EOMONTH return?

Answers: TODAY; MONTH; NETWORKDAYS; month-end date.

FAQ

They may be stored as text instead of real Excel dates. Convert them to proper date values before calculating.
Yes, when the dashboard needs dynamic aging or overdue calculations that refresh automatically.