Why WEEKDAY and WORKDAY in Google Sheets? - Purpose & Use Cases

The Big Idea

Discover how to make your date calculations foolproof and effortless with just two simple functions!

The Scenario

Imagine you have a list of dates and you need to know which day of the week each date falls on, or you want to find the next working day after a holiday or weekend.

Doing this by hand means checking calendars, counting days, and skipping weekends manually.

The Problem

Manually checking each date is slow and easy to mess up, especially if you have many dates.

You might forget to skip weekends or holidays, causing errors in your planning or reports.

The Solution

The WEEKDAY and WORKDAY functions automatically tell you the day of the week for any date and calculate future working days, skipping weekends and holidays.

This saves time and avoids mistakes, making your work more reliable.

Before vs After

✗ Before

Check calendar for each date; count days; skip weekends by memory

✓ After

WEEKDAY(date)  // returns day number
WORKDAY(start_date, days)  // returns next working day

What It Enables

You can quickly plan schedules, track deadlines, and analyze dates without worrying about weekends or holidays.

Real Life Example

A manager wants to know the weekday of each invoice date and find the next business day to schedule payments, avoiding weekends and holidays automatically.

Key Takeaways

Manual date checks are slow and error-prone.

WEEKDAY and WORKDAY automate day calculations and skip non-working days.

This makes scheduling and date analysis fast and accurate.

Practice

1. What does the WEEKDAY function return when given a date in Google Sheets?

easy

A. The name of the month for that date

B. The date of the next working day

C. The number of days between two dates

D. A number representing the day of the week for that date

Solution

1. Step 1: Understand the purpose of WEEKDAY

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

2. Step 2: Compare options with function behavior

   Only a number representing the day of the week for that date correctly describes this behavior; others describe unrelated functions.

3. Final Answer:

   A number representing the day of the week for that date -> Option D

4. Quick Check:

   WEEKDAY = day number [OK]

Hint: WEEKDAY gives day number, not names or intervals [OK]

Common Mistakes:

• Thinking WEEKDAY returns the month's name
• Confusing WEEKDAY with date difference functions
• Assuming WEEKDAY returns the next workday

2. Which of the following is the correct syntax to add 5 working days to a date in cell A1, skipping weekends in Google Sheets?

easy

A. =WEEKDAY(A1 + 5)

B. =WORKDAY(A1, 5)

C. =WORKDAY(5, A1)

D. =WORKDAY(A1 + 5)

Solution

1. Step 1: Recall WORKDAY function syntax

   WORKDAY(start_date, days, [holidays]) adds working days to start_date, skipping weekends.

2. Step 2: Check each option's syntax

   =WORKDAY(A1, 5) correctly uses WORKDAY with start_date A1 and 5 days. Others misuse argument order or functions.

3. Final Answer:

   =WORKDAY(A1, 5) -> Option B

4. Quick Check:

   WORKDAY(start_date, days) [OK]

Hint: WORKDAY(start_date, days) adds workdays skipping weekends [OK]

Common Mistakes:

• Swapping arguments in WORKDAY
• Using WEEKDAY instead of WORKDAY to add days
• Adding days directly without WORKDAY

3. If cell A1 contains the date 2024-06-14 (a Friday), what will =WORKDAY(A1, 3) return?

medium

A. 2024-06-19 (Wednesday)

B. 2024-06-18 (Tuesday)

C. 2024-06-17 (Monday)

D. 2024-06-20 (Thursday)

Solution

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

   Start date is Friday, June 14, 2024. We add 3 working days skipping weekends.

2. Step 2: Count 3 working days skipping weekend

   Day 1: Monday, June 17
   Day 2: Tuesday, June 18
   Day 3: Wednesday, June 19

3. Final Answer:

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

4. Quick Check:

   WORKDAY skips weekends, so 3 workdays after Friday is Wednesday [OK]

Hint: Count workdays skipping Sat/Sun after start date [OK]

Common Mistakes:

• Counting weekend days as workdays
• Adding days directly without WORKDAY
• Misidentifying the weekday of the start date

4. The formula =WORKDAY(A1, 10, C1:C3) returns an error. What is the most likely cause?

medium

A. WORKDAY cannot accept a range for holidays

B. The second argument must be a date, not a number

C. The holidays range C1:C3 contains invalid dates

D. The start date in A1 is not a valid date

Solution

1. Step 1: Understand WORKDAY arguments

   WORKDAY(start_date, days, [holidays]) expects holidays as valid dates in a range.

2. Step 2: Identify common error with holidays

   If holidays range contains invalid or text values, WORKDAY returns an error.

3. Final Answer:

   The holidays range C1:C3 contains invalid dates -> Option C

4. Quick Check:

   Invalid holiday dates cause WORKDAY errors [OK]

Hint: Check holiday dates for validity if WORKDAY errors [OK]

Common Mistakes:

• Assuming days argument must be a date
• Thinking WORKDAY can't accept holiday ranges
• Ignoring invalid or text values in holidays

5. You want to find the weekday number of the date that is 7 working days after 2024-06-10, excluding weekends and the holidays in range B1:B2. Which formula correctly does this?

hard

A. =WEEKDAY(WORKDAY(DATE(2024,6,10), 7, B1:B2))

B. =WORKDAY(WEEKDAY(DATE(2024,6,10)), 7, B1:B2)

C. =WEEKDAY(DATE(2024,6,10) + 7)

D. =WORKDAY(DATE(2024,6,10), 7) + WEEKDAY(B1:B2)

Solution

1. Step 1: Calculate the date 7 working days after June 10, 2024

   Use WORKDAY with start date DATE(2024,6,10), days 7, and holidays B1:B2 to skip weekends and holidays.

2. Step 2: Find the weekday number of the resulting date

   Wrap the WORKDAY result inside WEEKDAY to get the day number of that date.

3. Final Answer:

   =WEEKDAY(WORKDAY(DATE(2024,6,10), 7, B1:B2)) -> Option A

4. Quick Check:

   WORKDAY then WEEKDAY gives weekday number after skipping holidays [OK]

Hint: Use WORKDAY inside WEEKDAY to get weekday number after workdays [OK]

Common Mistakes:

• Using WEEKDAY before WORKDAY
• Adding days directly ignoring holidays
• Trying to add WEEKDAY results to dates