Why WEEKDAY and WORKDAY in Excel? - Purpose & Use Cases

The Big Idea

Discover how to make your date calculations effortless and error-free with just two simple functions!

The Scenario

Imagine you have a list of dates and you need to find out which day of the week each date falls on, or calculate a future date skipping weekends and holidays manually.

For example, planning project deadlines or scheduling meetings without including weekends can be tricky.

The Problem

Doing this by hand means counting days on a calendar, checking each date if it's a weekend or holiday, and then adjusting your plans.

This is slow, easy to mess up, and hard to update if your dates change.

The Solution

The WEEKDAY and WORKDAY functions in Excel do this work for you automatically.

WEEKDAY tells you the day number of the week for any date, and WORKDAY calculates a future or past date skipping weekends and holidays.

This saves time and avoids mistakes.

Before vs After

✗ Before

Check calendar day by day and mark weekends manually

✓ After

=WEEKDAY(A1) and =WORKDAY(A1, 5, holidays)

What It Enables

You can quickly find weekdays or calculate working days for scheduling without errors or extra effort.

Real Life Example

A manager can use WORKDAY to set a project deadline 10 working days from today, automatically skipping weekends and company holidays.

Key Takeaways

Manual date checks are slow and error-prone.

WEEKDAY and WORKDAY automate day calculations.

They help plan schedules easily and accurately.

Practice

1. What does the Excel function =WEEKDAY(A1) return when A1 contains a date?

easy

A. The date of the next workday after the date in A1

B. A number representing the day of the week for the date in A1

C. The total number of workdays in the month of A1

D. The name of the day (like Monday) for the date in A1

Solution

1. Step 1: Understand WEEKDAY function purpose

   The WEEKDAY function returns a number from 1 to 7 representing the day of the week for a given date.

2. Step 2: Apply to cell A1

   Since A1 contains a date, =WEEKDAY(A1) returns the day number of that date.

3. Final Answer:

   A number representing the day of the week for the date in A1 -> Option B

4. Quick Check:

   WEEKDAY = day number [OK]

Hint: WEEKDAY gives day number, not name or date [OK]

Common Mistakes:

• Thinking WEEKDAY returns the day name
• Confusing WEEKDAY with WORKDAY
• Expecting a date instead of a number

2. Which of these is the correct syntax to find the next workday after the date in cell B2, excluding weekends?

easy

A. =WORKDAY(B2, 1)

B. =WORKDAY(B2 + 1)

C. =WEEKDAY(B2, 1)

D. =WORKDAY(B2, "next")

Solution

1. Step 1: Recall WORKDAY syntax

   WORKDAY(start_date, days) returns the date after adding 'days' workdays to start_date, skipping weekends.

2. Step 2: Apply to find next workday

   To find the next workday after B2, add 1 workday: =WORKDAY(B2, 1) is correct syntax.

3. Final Answer:

   =WORKDAY(B2, 1) -> Option A

4. Quick Check:

   WORKDAY(date, 1) = next workday [OK]

Hint: WORKDAY needs two arguments: date and days [OK]

Common Mistakes:

• Using WORKDAY with only one argument
• Confusing WEEKDAY with WORKDAY
• Passing text like "next" instead of a number

3. If cell C3 contains the date 2024-06-14 (a Friday), what will =WORKDAY(C3, 3) return?

medium

A. 2024-06-17 (Monday)

B. 2024-06-18 (Tuesday)

C. 2024-06-20 (Thursday)

D. 2024-06-19 (Wednesday)

Solution

1. Step 1: Identify start date and days to add

   Start date is 2024-06-14 (Friday). We add 3 workdays, skipping weekends.

2. Step 2: Count workdays skipping weekend

   Adding 1 workday: Monday 2024-06-17
   Adding 2 workdays: Tuesday 2024-06-18
   Adding 3 workdays: Wednesday 2024-06-19

3. Final Answer:

   2024-06-19 (Wednesday) -> Option D

4. Quick Check:

   WORKDAY adds days skipping weekends [OK]

Hint: Count only weekdays, skip Sat & Sun [OK]

Common Mistakes:

• Counting weekend days as workdays
• Adding days directly without WORKDAY
• Confusing date formats

4. The formula =WORKDAY(A1, 5, {"2024-06-19"}) returns an error. What is the likely cause?

medium

A. WORKDAY does not accept a third argument

B. The days argument cannot be a positive number

C. The holidays argument must be a range, not an array of text strings

D. The date in A1 is invalid

Solution

1. Step 1: Understand WORKDAY holiday argument

   The third argument for WORKDAY is a range or array of dates, not text strings in quotes.

2. Step 2: Identify error cause

   Using {"2024-06-19"} passes a text string, not a date value, causing an error.

3. Final Answer:

   The holidays argument must be a range, not an array of text strings -> Option C

4. Quick Check:

   Holidays must be date values, not text [OK]

Hint: Holidays must be date cells or date arrays, not text [OK]

Common Mistakes:

• Passing holiday dates as text strings
• Ignoring the third argument format
• Assuming WORKDAY only takes two arguments

5. You want to find the weekday number of the date that is 10 workdays after 2024-06-01, excluding weekends and the holiday 2024-06-12. Which formula correctly does this?

hard

A. =WEEKDAY(WORKDAY("2024-06-01", 10, DATE(2024,6,12)))

B. =WORKDAY(WEEKDAY("2024-06-01"), 10, DATE(2024,6,12))

C. =WEEKDAY(WORKDAY("2024-06-01", 10, {"2024-06-12"}))

D. =WORKDAY("2024-06-01", 10, "2024-06-12")

Solution

1. Step 1: Calculate date 10 workdays after 2024-06-01 excluding holiday

   Use WORKDAY with start date, days, and holiday as DATE(2024,6,12) to get correct date.

2. Step 2: Find weekday number of that date

   Wrap WORKDAY result inside WEEKDAY to get the day number.

3. Final Answer:

   =WEEKDAY(WORKDAY("2024-06-01", 10, DATE(2024,6,12))) -> Option A

4. Quick Check:

   WORKDAY then WEEKDAY for weekday number [OK]

Hint: Use WORKDAY first, then WEEKDAY to get day number [OK]

Common Mistakes:

• Passing holiday as text instead of DATE function
• Using WEEKDAY inside WORKDAY incorrectly
• Ignoring holidays in WORKDAY