In MariaDB, DAYNAME() is a built-in date and time function that returns the name of the weekday for a given date.
It accepts one argument, which is the date you want to extract the day name from.
Return the Language used for Date & Time Functions in MariaDB
MariaDB has a lc_time_names system variable that controls the language used by the DAYNAME(), MONTHNAME() and DATE_FORMAT() date and time functions.
Here’s how to return the value of that variable.
MariaDB DAY() Explained
In MariaDB, DAY() is a synonym for DAYOFMONTH(). It returns the day of the month from a given date.
How DAYOFMONTH() Works in MariaDB
In MariaDB, DAYOFMONTH() is a built-in date and time function that returns the day of the month from a given date.
It accepts one argument, which is the date you want to extract the day of the month from.
The result is in the range 1 to 31. However, if the date has a zero day part (for example '0000-00-00' or '2021-00-00'), the result is 0.
How to Show all Locales in MariaDB
MariaDB supports a large list of locales that are used by functions such as DAYNAME(), MONTHNAME() and DATE_FORMAT().
While these locales are available to MariaDB, by default they’re not loaded into any of the system tables, so you can’t run a query to retrieve them.
However, MariaDB provides a plugin that does load these into a table. Once the plugin has been installed, you can query that table to return the locales available in MariaDB.
Date & Time Locales Available in MariaDB
Below is a full list of date and time locales available in MariaDB.
How DATE_FORMAT() Works in MariaDB
In MariaDB, DATE_FORMAT() is a built-in date and time function that formats a date according to the given format string.
It requires two arguments; the date and the format string. It also accepts an optional third argument that allows you to specify the locale.
MariaDB Date Format Strings
Below is a full list of format specifiers that can be used in format strings with functions like DATE_FORMAT(), STR_TO_DATE(), and FROM_UNIXTIME() in MariaDB.
How DATEDIFF() Works in MariaDB
In MariaDB, DATEDIFF() is a built-in date and time function that returns the difference, in days, between two dates.
It accepts two arguments, both of which are date or datetime expressions. It then subtracts the second date from the first.
How DATE() Works in MariaDB
In MariaDB, DATE() is a built-in date and time function that extracts the date part of a date or datetime expression.
You pass the date/datetime expression as an argument when calling the function.