How YEARWEEK() Works in MariaDB

In MariaDB, YEARWEEK() is a built-in date and time function that returns the year and week for a given date.

It accepts two arguments; the date you want to extract the year and week from, and an optional mode argument to specify the mode to use in the result.

It returns the week as a number in the range 0 to 53 or 1 to 53, depending on the mode being used. Also, the year in the result may be different from the year in the date argument for the first and the last week of the year.

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How HOUR() Works in MariaDB

In MariaDB, HOUR() is a built-in date and time function that returns the hour from a given time expression.

It accepts one argument, which is the time you want to extract the hour from.

For time-of-day values, it returns the hour as a number in the range 0 to 23. However, the range of TIME values can be much larger, and therefore, the returned value can be much higher than 23.

The return value is always positive, even if a negative time is provided.

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How WEEKDAY() Works in MariaDB

In MariaDB, WEEKDAY() is a built-in date and time function that returns the week day from a given date.

It accepts one argument, which is the date you want to extract the week day from.

It returns the day as a number. The index numbering starts at zero for Monday (i.e. 0 = Monday, 1 = Tuesday, etc). This is in contrast to DAYOFWEEK(), which adheres to the ODBC standard (1 = Sunday, 2 = Monday, etc).

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