# How to use the MySQL TO_DAYS() function

In this article, we will learn how to use the MySQL `TO_DAYS()`

function, which returns the number of days from year 0 to a given date.

In this article, we will learn how to use the MySQL `TO_DAYS()`

function, which returns the number of days from year 0 to a given date. We will also see some examples of how to use this function in different situations, and explore some related functions that can be helpful for working with dates and days.

## Syntax

The syntax of the `TO_DAYS()`

function is as follows:

```
TO_DAYS(date)
```

The `date`

parameter can be any valid date or datetime expression, or a string that can be converted to a date or datetime value. If the `date`

parameter is NULL, the function returns NULL. The `TO_DAYS()`

function returns an integer value that represents the number of days from year 0 to the given date. For example, `TO_DAYS('2023-01-15')`

returns 738150, which is the number of days from year 0 to the date ‘2023-01-15’.

## Examples

Let’s see some examples of how to use the `TO_DAYS()`

function in MySQL.

### Example 1: Get the number of days from year 0 to a date value

We can use the `TO_DAYS()`

function to get the number of days from year 0 to a date value. For example:

```
SELECT TO_DAYS('2023-01-15') AS result;
```

This query will return the number of days from year 0 to the date value ‘2023-01-15’. The query will return 738150, which is the number of days from year 0 to the date value.

### Example 2: Get the number of days from year 0 to a datetime value

We can use the `TO_DAYS()`

function to get the number of days from year 0 to a datetime value. For example:

```
SELECT TO_DAYS('2023-01-15 10:02:34') AS result;
```

This query will return the number of days from year 0 to the datetime value ‘2023-01-15 10:02:34’. The query will return 738150, which is the same as the number of days from year 0 to the date part of the datetime value.

### Example 3: Get the number of days from year 0 to a string value

We can use the `TO_DAYS()`

function to get the number of days from year 0 to a string value that can be converted to a date or datetime value. For example:

```
SELECT TO_DAYS('January 15, 2023') AS result;
```

This query will return the number of days from year 0 to the string value ‘January 15, 2023’ that can be converted to a date value. The query will return 738150, which is the same as the number of days from year 0 to the date value ‘2023-01-15’.

### Example 4: Get the difference between two date values in days

We can use the `TO_DAYS()`

function with the `DATEDIFF()`

function, which returns the difference between two date values, to get the difference between two date values in days. For example:

```
SELECT DATEDIFF(TO_DAYS('2023-01-15'), TO_DAYS('2023-01-14')) AS result;
```

This query will return the difference between the two date values ‘2023-01-15’ and ‘2023-01-14’ in days. The query will use the `TO_DAYS()`

function to convert the date values to the number of days from year 0, and then use the `DATEDIFF()`

function to get the difference between them. The query will return 1, which is the number of days between the two date values.

### Example 5: Get the difference between two datetime values in days

We can use the `TO_DAYS()`

function with the `DATEDIFF()`

function, which returns the difference between two date values, to get the difference between two datetime values in days. For example:

```
SELECT DATEDIFF(TO_DAYS('2023-01-15 10:02:34'), TO_DAYS('2023-01-14 09:00:00')) AS result;
```

This query will return the difference between the two datetime values ‘2023-01-15 10:02:34’ and ‘2023-01-14 09:00:00’ in days. The query will use the `TO_DAYS()`

function to convert the datetime values to the number of days from year 0, and then use the `DATEDIFF()`

function to get the difference between them. The query will return 1, which is the same as the number of days between the date parts of the datetime values.

## Related Functions

There are some other functions that are related to the `TO_DAYS()`

function, and can be useful for working with dates and days. Here are some of them:

: This function returns the date part of a date or datetime value, or a string that can be converted to a date value. For example,`DATE()`

`DATE('2023-01-15 10:02:34')`

returns ‘2023-01-15’.: This function returns the datetime value of a date or datetime value, or a string that can be converted to a datetime value. For example,`DATETIME()`

`DATETIME('2023-01-15 10:02:34')`

returns ‘2023-01-15 10:02:34’.: This function returns the timestamp value of a date, datetime, or timestamp value, or a string that can be converted to a timestamp value. For example,`TIMESTAMP()`

`TIMESTAMP('2023-01-15 10:02:34')`

returns ‘2023-01-15 10:02:34’.: This function returns the difference between two date values. For example,`DATEDIFF()`

`DATEDIFF('2023-01-15', '2023-01-14')`

returns 1, which is the number of days between the two date values.: This function returns the date value that corresponds to the number of days from year 0. For example,`FROM_DAYS()`

`FROM_DAYS(738150)`

returns ‘2023-01-15’, which is the date value that corresponds to the number of days from year 0.

## Conclusion

In this article, we learned how to use the MySQL `TO_DAYS()`

function, which returns the number of days from year 0 to a given date. We also saw some examples of how to use this function in different situations, and explored some related functions that can be helpful for working with dates and days.