You can use the following formula in Excel to find the first Monday of a given month:

=DATE(YEAR(A2),MONTH(A2),7)-WEEKDAY(DATE(YEAR(A2),MONTH(A2),7),3)

This particular example returns the first Monday of the month for the date in cell **A2**.

The following example shows how to use this formula in practice.

**Example: Find First Monday of Month in Excel**

Suppose we have the following list of dates in Excel:

We can type the following formula into cell **B2** to find the first Monday of the month for the date in cell **A2**:

=DATE(YEAR(A2),MONTH(A2),7)-WEEKDAY(DATE(YEAR(A2),MONTH(A2),7),3)

We can then click and drag this formula down to each remaining cell in column B

Column B now contains the date of the first Monday of each month in column A.

For example, the first date of **1/1/2023** contains the month of January for 2023.

We can confirm that **1/2/2023** is indeed the first Monday of this month by referring to a calendar:

Similarly, the second date of **2/1/2023** contains the month of February for 2023.

We can confirm that **2/6/2023** is indeed the first Monday of this month by referring to a calendar:

**How This Formula Works**

Recall the formula that we used to find the first Monday of the date 1/1/2023:

=DATE(YEAR(A2),MONTH(A2),7)-WEEKDAY(DATE(YEAR(A2),MONTH(A2),7),3)

Here is how this formula works:

First, we use the **DATE**, **MONTH** and **YEAR** functions to extract the seventh day of the month and year in cell **A2**. This returns **1/7/2023**.

Next, we use the **WEEKDAY** function with the optional argument of **3** to specify that we would like to extract the number of the day of the week of **1/7/2023**, assuming that the days are number from 0 (Monday) to 6 (Sunday).

This returns **5** since **1/7/2023** is on a Saturday.

Lastly, we use a subtraction sign to subtract **5** from **1/7/2023** to get **1/2/2023**.

We use the same logic to find the first Monday of each date.

**Note**: You can find the complete documentation for the **WEEKDAY** function in Excel here.

**Additional Resources**

The following tutorials explain how to perform other common tasks in Excel:

How to Calculate Average by Month in Excel

How to Calculate the Average by Group in Excel

How to Calculate 7-Day Moving Average in Excel