What is the method for obtaining the first day of a quarter in MySQL?

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You can use the following syntax to get the first day of the quarter for a given date in MySQL:

SELECT sales_date, MAKEDATE(YEAR(sales_date), 1) +
                   INTERVAL QUARTER(sales_date) QUARTER -
                   INTERVAL 1 QUARTER AS first_day
FROM sales;

This particular example creates a new column named first_day that contains the first day of the quarter for the corresponding date in the sales_date column of the table named sales.

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

Example: How to Get First Day of Quarter in MySQL

Suppose we have the following table named sales that contains information about sales made at various grocery stores on various dates:

-- create table 
CREATE TABLE sales (
  store_ID INT PRIMARY KEY,
  item TEXT NOT NULL,
  sales_date DATE NOT NULL
);

-- insert rows into table
INSERT INTO sales VALUES (0001, 'Oranges', '2024-02-10');
INSERT INTO sales VALUES (0002, 'Apples', '2024-11-25');
INSERT INTO sales VALUES (0003, 'Bananas', '2024-07-30');
INSERT INTO sales VALUES (0004, 'Melons', '2024-01-14');
INSERT INTO sales VALUES (0005, 'Grapes', '2024-05-19');

-- view all rows in table
SELECT * FROM sales;

Output:

+----------+---------+------------+
| store_ID | item    | sales_date |
+----------+---------+------------+
|        1 | Oranges | 2024-02-10 |
|        2 | Apples  | 2024-11-25 |
|        3 | Bananas | 2024-07-30 |
|        4 | Melons  | 2024-01-14 |
|        5 | Grapes  | 2024-05-19 |
+----------+---------+------------+

Suppose that we would like to select the dates from the sales_date column and create a new column that contains the first day of the quarter for each corresponding date in the sales_date column.

We can use the following syntax to do so:

SELECT sales_date, MAKEDATE(YEAR(sales_date), 1) +
                   INTERVAL QUARTER(sales_date) QUARTER -
                   INTERVAL 1 QUARTER AS first_day
FROM sales;

Output:

+------------+------------+
| sales_date | first_day  |
+------------+------------+
| 2024-02-10 | 2024-01-01 |
| 2024-11-25 | 2024-10-01 |
| 2024-07-30 | 2024-07-01 |
| 2024-01-14 | 2024-01-01 |
| 2024-05-19 | 2024-04-01 |
+------------+------------+

Notice that the dates in the first_day column represent the first day of the quarter for the corresponding date in the sales_date column.

For example:

• The first day of the quarter for the date 2/1/2024 is 1/1/2024.
• The first day of the quarter for the date 11/25/2024 is 10/1/2024.
• The first day of the quarter for the date 7/30/2024 is 7/1/2024.

Additional Resources

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

MySQL: How to Select Rows where Date is Equal to Today