# WEEKDAY Function in Microsoft Excel

## Part 1: Introduction

### Definition

The WEEKDAY function in Microsoft Excel is a date/time function that returns the day of the week corresponding to a date. By default, the day is given as an integer, ranging from 1 (Sunday) to 7 (Saturday).

### Purpose

The purpose of the WEEKDAY function is to provide the day of the week for a specific date. This can be useful for scheduling, planning, and data analysis tasks based on the day of the week.

### Syntax & Arguments

The syntax for the WEEKDAY function is as follows:

syntax
```WEEKDAY(serial_number,[return_type]) ```

The WEEKDAY function syntax has the following arguments:

• Serial_number: Required. A sequential number that represents the date of the day you are trying to find. Dates should be entered using the DATE function or as a result of other formulas or functions.

• Return_type: Optional. A number that determines the type of return value. It can be a number from 1 to 17, each representing a different numbering system for the days of the week.

### Return Value

The WEEKDAY function returns an integer from 1 to 7, representing the day of the week. The specific value returned depends on the return_type argument.

### Remarks

Excel stores date as sequential serial numbers to be used in calculations. By default, January 1, 1900, is serial number 1, and January 1, 2008, is serial number 39448 because it is 39,448 days after January 1, 1900. If serial_number is out of range for the current date base value, a #NUM! Error is returned if return_type is out of the range specified in the table above, a #NUM! Error is returned.

## Part 2: Examples

Let’s look at examples of using the WEEKDAY function in business.

### Example 1

Purpose: To find the day of the week for a specific date.

Data tables and formulas:

A
1Date
22023-07-29
3=WEEKDAY(A2)

Explanation: In this example, we want to find the day of the week for the date in cell A2. The formula `=WEEKDAY(A2)` returns the day of the week for the date in cell A2.

### Example 2

Purpose: To find the day of the week for a specific date, with Monday as 1 and Sunday as 7.

Data tables and formulas:

A
1Date
22023-07-29
3=WEEKDAY(A2, 2)

Explanation: In this example, we want to find the day of the week for the date in cell A2, with Monday as 1 and Sunday as 7. The formula `=WEEKDAY(A2, 2)` returns the day of the week for the date in cell A2.

### Example 3

Purpose: To find the day of the week for a specific date, with Monday as 0 and Sunday as 6.

Data tables and formulas:

A
1Date
22023-07-29
3=WEEKDAY(A2, 3)

Explanation: In this example, we want to find the day of the week for the date in cell A2, with Monday as 0 and Sunday as 6. The formula `=WEEKDAY(A2, 3)` returns the day of the week for the date in cell A2.

### Example 4

Purpose: To find the day of the week for a specific date, with Tuesday as 1 and Monday as 7.

Data tables and formulas:

A
1Date
22023-07-29
3=WEEKDAY(A2, 12)

Explanation: In this example, we want to find the day of the week for the date in cell A2, with Tuesday as 1 and Monday as 7. The formula `=WEEKDAY(A2, 12)` returns the day of the week for the date in cell A2.

### Example 5

Purpose: To find the day of the week for a specific date, with Wednesday as 1 and Tuesday as 7.

Data tables and formulas:

A
1Date
22023-07-29
3=WEEKDAY(A2, 13)

Explanation: In this example, we want to find the day of the week for the date in cell A2, with Wednesday as 1 and Tuesday as 7. The formula `=WEEKDAY(A2, 13)` returns the day of the week for the date in cell A2.

### Example 6: Using WEEKDAY with IF Function

Purpose: To classify whether a given date is a weekday or a weekend.

Data tables and formulas:

AB
1DateDay Type
22023-07-29=IF(WEEKDAY(A2,2)<6, “Weekday”, “Weekend”)

Explanation: In this example, we want to classify whether the date in cell A2 is a weekday or a weekend. The formula `=IF(WEEKDAY(A2,2)<6, "Weekday", "Weekend")` returns “Weekday” if the date is a weekday and “Weekend” if the date is a weekend.

### Example 7: Using WEEKDAY with VLOOKUP Function

Purpose: To find the name of the day for a specific date.

Data tables and formulas:

AB
1DateDay Name
22023-07-29=VLOOKUP(WEEKDAY(A2,2), \$E\$2:\$F\$8, 2, FALSE)

And the lookup table:

EF
1NumberDay
21Monday
32Tuesday
43Wednesday
54Thursday
65Friday
76Saturday
87Sunday

Explanation: In this example, we want to find the name of the day for the date in cell A2. The formula `=VLOOKUP(WEEKDAY(A2,2), \$E\$2:\$F\$8, 2, FALSE)` returns the name of the day for the date in cell A2.

### Example 8: Using WEEKDAY with SUM Function

Purpose: To sum values corresponding to a specific day of the week.

Data tables and formulas:

ABC
1DateValueSum of Mondays
22023-07-2910=SUMIF(A2:A4, WEEKDAY(A2:A4,2)=1, B2:B4)
32023-07-3020
42023-07-3130

Explanation: In this example, we want to sum column B values corresponding to Monday. The formula `=SUMIF(A2:A4, WEEKDAY(A2:A4,2)=1, B2:B4)` returns the sum of the values that correspond to Monday.

### Example 9: Using WEEKDAY with AVERAGE Function

Purpose: To calculate the average values corresponding to a specific day of the week.

Data tables and formulas:

ABC
1DateValueAverage of Mondays
22023-07-2910=AVERAGEIF(A2:A4, WEEKDAY(A2:A4,2)=1, B2:B4)
32023-07-3020
42023-07-3130

Explanation: In this example, we want to calculate the average values in column B that correspond to Monday. The formula `=AVERAGEIF(A2:A4, WEEKDAY(A2:A4,2)=1, B2:B4)` returns the standard of the values that correspond to Monday.

### Example 10: Using WEEKDAY with COUNT Function

Purpose: To count the number of specific days of the week on various dates.

Data tables and formulas:

AB
1DateCount of Mondays
22023-07-29=COUNTIF(A2:A4, WEEKDAY(A2:A4,2)=1)
32023-07-30
42023-07-31

Explanation: In this example, we want to count the number of Mondays in the range A2:A4. The formula `=COUNTIF(A2:A4, WEEKDAY(A2:A4,2)=1)` returns the count of Mondays in the range A2:A4.

### Example 11: Using WEEKDAY with MAX Function

Purpose: To find the maximum value corresponding to a specific day of the week.

Data tables and formulas:

ABC
1DateValueMax of Mondays
22023-07-2910=MAXIFS(B2:B4, A2:A4, WEEKDAY(A2:A4,2)=1)
32023-07-3020
42023-07-3130

Explanation: In this example, we want to find the maximum value in column B that corresponds to Monday. The formula `=MAXIFS(B2:B4, A2:A4, WEEKDAY(A2:A4,2)=1)` returns the maximum weight that fits Monday.

### Example 12: Using WEEKDAY with MIN Function

Purpose: To find the minimum value corresponding to a specific day of the week.

Data tables and formulas:

ABC
1DateValueMin of Mondays
22023-07-2910=MINIFS(B2:B4, A2:A4, WEEKDAY(A2:A4,2)=1)
32023-07-3020
42023-07-3130

Explanation: In this example, we want to find the minimum value in column B that corresponds to Monday. The formula `=MINIFS(B2:B4, A2:A4, WEEKDAY(A2:A4,2)=1)` returns the minimum value that corresponds to Monday.

### Example 13: Using WEEKDAY with INDEX and MATCH Functions

Purpose: To find the value corresponding to the first Monday in a range of dates.

Data tables and formulas:

ABC
1DateValueValue on First Monday
22023-07-2910=INDEX(B2:B4, MATCH(1, WEEKDAY(A2:A4,2)=1, 0))
32023-07-3020
42023-07-3130

Explanation: In this example, we want to find the value in column B corresponding to the first Monday in the range A2:A4. The formula `=INDEX(B2:B4, MATCH(1, WEEKDAY(A2:A4,2)=1, 0))` returns the value that corresponds to the first Monday in the range A2:A4.

## Part 3: Tips and Tricks

1. The WEEKDAY function can be combined to create more complex formulas. For example, you can use it with the IF function to perform different calculations based on the day of the week.

2. Remember that Excel stores date as sequential serial numbers so that you can use these numbers in calculations.

3. The WEEKDAY function can be helpful in scheduling and planning tasks that are based on the day of the week.

4. The return_type argument allows you to adjust the numbering system for the days of the week to suit your needs.