n false;
					}
				}

				$value = array_map( 'intval', $value );

				return $value[0] . ' AND ' . $value[1];

			default:
				if ( ! is_numeric( $value ) ) {
					return false;
				}

				return (int) $value;
		}
	}

	/**
	 * Builds a MySQL format date/time based on some query parameters.
	 *
	 * You can pass an array of values (year, month, etc.) with missing parameter values being defaulted to
	 * either the maximum or minimum values (controlled by the $default_to parameter). Alternatively you can
	 * pass a string that will be passed to date_create().
	 *
	 * @since 3.7.0
	 *
	 * @param string|array $datetime       An array of parameters or a strotime() string
	 * @param bool         $default_to_max Whether to round up incomplete dates. Supported by values
	 *                                     of $datetime that are arrays, or string values that are a
	 *                                     subset of MySQL date format ('Y', 'Y-m', 'Y-m-d', 'Y-m-d H:i').
	 *                                     Default: false.
	 * @return string|false A MySQL format date/time or false on failure
	 */
	public function build_mysql_datetime( $datetime, $default_to_max = false ) {
		if ( ! is_array( $datetime ) ) {

			/*
			 * Try to parse some common date formats, so we can detect
			 * the level of precision and support the 'inclusive' parameter.
			 */
			if ( preg_match( '/^(\d{4})$/', $datetime, $matches ) ) {
				// Y
				$datetime = array(
					'year' => (int) $matches[1],
				);

			} elseif ( preg_match( '/^(\d{4})\-(\d{2})$/', $datetime, $matches ) ) {
				// Y-m
				$datetime = array(
					'year'  => (int) $matches[1],
					'month' => (int) $matches[2],
				);

			} elseif ( preg_match( '/^(\d{4})\-(\d{2})\-(\d{2})$/', $datetime, $matches ) ) {
				// Y-m-d
				$datetime = array(
					'year'  => (int) $matches[1],
					'month' => (int) $matches[2],
					'day'   => (int) $matches[3],
				);

			} elseif ( preg_match( '/^(\d{4})\-(\d{2})\-(\d{2}) (\d{2}):(\d{2})$/', $datetime, $matches ) ) {
				// Y-m-d H:i
				$datetime = array(
					'year'   => (int) $matches[1],
					'month'  => (int) $matches[2],
					'day'    => (int) $matches[3],
					'hour'   => (int) $matches[4],
					'minute' => (int) $matches[5],
				);
			}

			// If no match is found, we don't support default_to_max.
			if ( ! is_array( $datetime ) ) {
				$wp_timezone = wp_timezone();

				// Assume local timezone if not provided.
				$dt = date_create( $datetime, $wp_timezone );

				if ( false === $dt ) {
					return gmdate( 'Y-m-d H:i:s', false );
				}

				return $dt->setTimezone( $wp_timezone )->format( 'Y-m-d H:i:s' );
			}
		}

		$datetime = array_map( 'absint', $datetime );

		if ( ! isset( $datetime['year'] ) ) {
			$datetime['year'] = current_time( 'Y' );
		}

		if ( ! isset( $datetime['month'] ) ) {
			$datetime['month'] = ( $default_to_max ) ? 12 : 1;
		}

		if ( ! isset( $datetime['day'] ) ) {
			$datetime['day'] = ( $default_to_max ) ? (int) gmdate( 't', mktime( 0, 0, 0, $datetime['month'], 1, $datetime['year'] ) ) : 1;
		}

		if ( ! isset( $datetime['hour'] ) ) {
			$datetime['hour'] = ( $default_to_max ) ? 23 : 0;
		}

		if ( ! isset( $datetime['minute'] ) ) {
			$datetime['minute'] = ( $default_to_max ) ? 59 : 0;
		}

		if ( ! isset( $datetime['second'] ) ) {
			$datetime['second'] = ( $default_to_max ) ? 59 : 0;
		}

		return sprintf( '%04d-%02d-%02d %02d:%02d:%02d', $datetime['year'], $datetime['month'], $datetime['day'], $datetime['hour'], $datetime['minute'], $datetime['second'] );
	}

	/**
	 * Builds a query string for comparing time values (hour, minute, second).
	 *
	 * If just hour, minute, or second is set than a normal comparison will be done.
	 * However if multiple values are passed, a pseudo-decimal time will be created
	 * in order to be able to accurately compare against.
	 *
	 * @since 3.7.0
	 *
	 * @param string   $column  The column to query against. Needs to be pre-validated!
	 * @param string   $compare The comparison operator. Needs to be pre-validated!
	 * @param int|null $hour    Optional. An hour value (0-23).
	 * @param int|null $minute  Optional. A minute value (0-59).
	 * @param int|null $second  Optional. A second value (0-59).
	 * @return string|false A query part or false on failure.
	 */
	public function build_time_query( $column, $compare, $hour = null, $minute = null, $second = null ) {
		global $wpdb;

		// Have to have at least one.
		if ( ! isset( $hour ) && ! isset( $minute ) && ! isset( $second ) ) {
			return false;
		}

		// Complex combined queries aren't supported for multi-value queries.
		if ( in_array( $compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ), true ) ) {
			$return = array();

			$value = $this->build_value( $compare, $hour );
			if ( false !== $value ) {
				$return[] = "HOUR( $column ) $compare $value";
			}

			$value = $this->build_value( $compare, $minute );
			if ( false !== $value ) {
				$return[] = "MINUTE( $column ) $compare $value";
			}

			$value = $this->build_value( $compare, $second );
			if ( false !== $value ) {
				$return[] = "SECOND( $column ) $compare $value";
			}

			return implode( ' AND ', $return );
		}

		// Cases where just one unit is set.
		if ( isset( $hour ) && ! isset( $minute ) && ! isset( $second ) ) {
			$value = $this->build_value( $compare, $hour );
			if ( false !== $value ) {
				return "HOUR( $column ) $compare $value";
			}
		} elseif ( ! isset( $hour ) && isset( $minute ) && ! isset( $second ) ) {
			$value = $this->build_value( $compare, $minute );
			if ( false !== $value ) {
				return "MINUTE( $column ) $compare $value";
			}
		} elseif ( ! isset( $hour ) && ! isset( $minute ) && isset( $second ) ) {
			$value = $this->build_value( $compare, $second );
			if ( false !== $value ) {
				return "SECOND( $column ) $compare $value";
			}
		}

		// Single units were already handled. Since hour & second isn't allowed, minute must to be set.
		if ( ! isset( $minute ) ) {
			return false;
		}

		$format = '';
		$time   = '';

		// Hour.
		if ( null !== $hour ) {
			$format .= '%H.';
			$time   .= sprintf( '%02d', $hour ) . '.';
		} else {
			$format .= '0.';
			$time   .= '0.';
		}

		// Minute.
		$format .= '%i';
		$time   .= sprintf( '%02d', $minute );

		if ( isset( $second ) ) {
			$format .= '%s';
			$time   .= sprintf( '%02d', $second );
		}

		return $wpdb->prepare( "DATE_FORMAT( $column, %s ) $compare %f", $format, $time );
	}

	/**
	 * Sanitizes a 'relation' operator.
	 *
	 * @since 6.0.3
	 *
	 * @param string $relation Raw relation key from the query argument.
	 * @return string Sanitized relation ('AND' or 'OR').
	 */
	public function sanitize_relation( $relation ) {
		if ( 'OR' === strtoupper( $relation ) ) {
			return 'OR';
		} else {
			return 'AND';
		}
	}
}