If you are managing a massive employee schedule in Excel, you frequently need to know exactly what day of the week a specific date falls on. If an employee requests “October 14th” off, looking at a wall calendar to figure out if that is a Tuesday or a Saturday takes too much time. Instead of guessing, you can use the highly specific WEEKDAY() function to force Excel to instantly calculate the exact day of the week for thousands of dates simultaneously.
How the WEEKDAY Function Works
Because Excel mathematically stores dates as sequential serial numbers, it inherently knows the chronological calendar. The WEEKDAY() function reaches into a date cell, performs a mathematical calculation based on the Gregorian calendar, and outputs a single digit representing the day of the week. By default, Excel considers Sunday to be Day 1, and Saturday to be Day 7.
Step-by-Step Instructions
Assume cell A1 contains a random date: 10/14/2026.
- Click on an empty cell (like B1) where you want the answer to appear.
- Type the following formula:
=WEEKDAY(A1)
- Press Enter.
Excel will instantly output the number 4. Because Sunday is Day 1, Day 4 means October 14th is a Wednesday.
Converting the Number into a Word
While the number “4” is mathematically correct, it is not helpful for human readability. You want the cell to literally say the word “Wednesday.” To achieve this, you do not need to change the formula; you simply need to change how the cell is formatted.
- Click on cell B1 (which currently displays the number 4).
- Right-click the cell and select Format Cells…
- In the dialogue box, look at the “Category” list on the left side and select Custom.
- Look for the text box labeled “Type:” and delete whatever is currently inside it.
- Type exactly four letter “d”s in a row:
dddd
(Note: Typing “ddd” will output “Wed,” while “dddd” will output the full word “Wednesday”).
- Click OK.
The number 4 will instantly vanish, replaced by the beautifully formatted word Wednesday. If you drag this formula down a list of 5,000 dates, Excel will instantly calculate and display the exact day of the week for every single row.