# DAYS360

The `DAYS360` function calculates the number of days between two dates based on a 360-day year. This formula is commonly used in financial calculations, such as calculating interest payments. The `method` parameter is optional and can be used to specify the type of day count basis to use, such as US (NASD), European (30/360), or actual/actual.

## Usage

Use the `DAYS360` formula with the syntax shown below, it has 2 required parameters and 1 optional parameter:

Parameters:
1. start_date (required):
The starting date of the date range to calculate the number of days between. Must be a valid date.
2. end_date (required):
The ending date of the date range to calculate the number of days between. Must be a valid date.
3. method (optional):
An optional parameter that specifies the type of day count basis to use. The default value is US (NASD). Other options include European (30/360) or actual/actual.

## Examples

Here are a few example use cases that explain how to use the `DAYS360` formula in Google Sheets.

### Calculate interest payments

Use `DAYS360` to calculate the number of days between two dates based on a 360-day year, which is commonly used in financial calculations such as calculating interest payments.

### Calculate employee work days

Use `DAYS360` to calculate the number of work days between two dates based on a 360-day year, which is commonly used in payroll calculations.

### Calculate inventory aging

Use `DAYS360` to calculate the age of inventory based on the number of days between the purchase date and the current date, based on a 360-day year.

## Common Mistakes

`DAYS360` not working? Here are some common mistakes people make when using the `DAYS360` Google Sheets Formula:

### Incorrect date format

The start_date and end_date arguments must be valid date formats. If they are not, the formula will return an error. Make sure the date format is correct or use the DATEVALUE function to convert text to date format.

### Invalid method

The method argument can only be set to 0 or 1. If any other value is used, the formula will return an error. Make sure the method argument is set correctly.

### Incorrect order of dates

The start_date argument must be earlier than the end_date argument. If they are reversed, the formula will return a negative number. Make sure the dates are in the correct order.

The following functions are similar to `DAYS360` or are often used with it in a formula:

• `DAYS`

The `DAYS` function calculates the number of days between two dates. It takes two date values as input: `end_date` and `start_date`. The function returns the number of days between the two dates, where the `end_date` is inclusive and the `start_date` is exclusive.

• `DATEDIF`

The `DATEDIF` function in Google Sheets calculates the difference between two dates using a specified unit of measurement. This function is commonly used to calculate the length of time between two dates, such as the number of days, months, or years. The function is particularly useful when working with financial or project planning data.

• `NETWORKDAYS`

The `NETWORKDAYS` function returns the number of working days between two given dates. This function excludes weekends (Saturday and Sunday) and optionally, any specified holidays. This function is commonly used in financial and business applications to calculate the number of workdays between two dates.

• `YEARFRAC`

The `YEARFRAC` function calculates the fraction of a year between two dates. This is useful for calculating the duration of time periods that are less than a year. The function takes into account leap years and can use different day count conventions to calculate the fraction of a year.

You can learn more about the `DAYS360` Google Sheets function on Google Support.