Are you looking for a way to retrieve the last day of the month in T-SQL? Look no further than the EOMONTH() function! In this article, we will cover how to use this function and provide an example query with results.

## Finding the Last Day of the Month in T-SQL

The EOMONTH() function is an extremely useful tool for retrieving the last date in a month. It takes one or two arguments.

The first argument is the date for which you want to retrieve the last day of the month. The second argument is optional and allows you to add or subtract a specified number of months from the date.

To use the EOMONTH() function, simply input the date you want to find the last day of the month for. For example, if you wanted to find the last day of the current month, you would input GETDATE().

This will return the last day of the current month.

If you want to add or subtract a specified number of months from the date, you can include an optional second argument.

To add, simply input a positive number. To subtract, input a negative number.

For example, if you wanted to find the last day of the previous month, you would input EOMONTH(GETDATE(), -1). This will return the last day of the previous month.

## Example Query and Results

Now that you know how to use the EOMONTH() function, let’s take a look at an example query and results. Suppose we have a table called Furniture that contains information about various furniture pieces, including the name and purchase date.

We want to add a column to our table that shows the last day of the month that the furniture was purchased.

To accomplish this, we can use the EOMONTH() function in our select statement.

Our query would look like this:

```
SELECT Name, PurchaseDate, EOMONTH(PurchaseDate) as LastDayDate
FROM Furniture
```

This will retrieve the name, purchase date, and last day of the month for each piece of furniture in our table. The result table would look like this:

Name | PurchaseDate | LastDayDate |
---|---|---|

Recliner | 2021-01-06 | 2021-01-31 |

Dining Table | 2021-02-14 | 2021-02-28 |

Bed Frame | 2021-03-22 | 2021-03-31 |

Sofa | 2021-04-18 | 2021-04-30 |

Desk | 2021-05-17 | 2021-05-31 |

As you can see, the LastDayDate column shows the last day of the month for each furniture purchase.

This allows us to easily sort and filter our data based on the last day of the month.

## Conclusion

In conclusion, the EOMONTH() function is a powerful tool for retrieving the last day of the month in T-SQL. By using this function, we can easily add a column to our table that shows the last day of the month for each record.

This allows us to better analyze and organize our data. So go ahead, try out the EOMONTH() function in your next T-SQL query!

## EOMONTH() Function Explained

The EOMONTH() function is a built-in function in T-SQL that returns the last day of the month for a given date or datetime expression. This function takes one mandatory argument, which is the date or datetime expression for which we want to retrieve the last day of the month.

This function is particularly useful for calculating financial statements, invoice schedules, or other time-based calculations.

### Argument Used in EOMONTH() Function

The mandatory argument in the EOMONTH() function is the date or datetime expression for which we want to retrieve the last day of the month. This argument must be specified in the form of a valid date or datetime expression.

Values of the date or datetime data type are the only valid inputs for the argument. For example, you could use the PurchaseDate column from the Furniture table as the argument.

### Returning Last Day of Same Month as Argument

The EOMONTH() function returns the date of the last day of the same month as the argument. That is, if we input a date or datetime expression corresponding to any day in a certain month, the function will return the last day of the same month.

Thus, the function always returns a value that falls within the same calendar month as the argument. For example, if we execute the following query:

`SELECT EOMONTH('2022-09-15')`

The result will be ‘2022-09-30’.

This is because September 30th is the last day of the month of September, which is the same month as the input argument ‘2022-09-15’.

### Adding or Subtracting Months with Optional Second Argument

The EOMONTH() function also allows us to add or subtract a specified number of months to the input argument. The second argument is optional and is used to specify the number of months we want to add or subtract to the input argument.

If we want to add months, we use a positive integer value, and if we want to subtract months, we use a negative integer value. For example, if we execute the following query:

`SELECT EOMONTH('2022-09-15', -2)`

The result will be ‘2022-07-31’.

This is because we input ‘2022-09-15’ as the first argument and -2 as the second argument. Thus, the EOMONTH() function subtracts two months from the input argument, resulting in ‘2022-07-15’.

The function then returns the last day of this month, which is ‘2022-07-31’. In addition to adding or subtracting months, we can also use the second argument to specify a date or datetime expression that serves as a starting point.

### For example:

`SELECT EOMONTH('2022-09-15', '2021-08-10')`

In this query, the second argument specifies ‘2021-08-10’ as the starting point. The EOMONTH() function then calculates the number of months difference between the starting point and the input argument, and returns the last day of the same month as the input argument.

## Conclusion

In conclusion, the EOMONTH() function is a powerful and versatile tool in T-SQL that can be used to retrieve the last day of the month for a given date or datetime expression. The function is flexible and allows us to add or subtract months from the input argument to return the last day of a specific month.

With the EOMONTH() function, we can easily create financial reports, invoice schedules, or other time-based calculations that require accurate and precise calculations of the last day of the month. In conclusion, the EOMONTH() function in T-SQL is a powerful and versatile tool for retrieving the last day of the month for a given date or datetime expression.

Its mandatory argument is a date or datetime expression that returns the last day of the same month as the argument. The optional second argument allows for the addition or subtraction of months to calculate the last day of a specific month.

By using the EOMONTH() function, we can easily create financial reports and invoice schedules, among other time-based calculations that require accurate calculations of the last day of the month. With its flexibility and usefulness, this function is an important tool in T-SQL.