Script to generate new rotations

new-rotations.php

<?php
echo 'Please paste previous lines:' . PHP_EOL;
$input = file_get_contents( 'php://stdin' );
echo PHP_EOL . '--------------------------------' . PHP_EOL;
$weeks = intval( $_SERVER['argv'][1] ?? 12 );
$lines = explode( PHP_EOL, trim( $input ) );
$ts = 0;
$i = 0;
$users = array();
foreach ( $lines as $line ) {
	preg_match( '#(?:<li>)?([^:]+):\s+@([^\s<]+)(?:</li>)?#', $line, $m );
	if ( empty( $m[2] ) ) {
		continue;
	}

	if ( ! in_array( $m[2], $users ) ) {
		$users[] = $m[2];
		$i++;
	} else {
		$i = ( $i + 1 ) % count( $users );
	}
	$ts = max( strtotime( $m[1] ), $ts );
}

if ( ! $weeks ) {
	$weeks = count( $lines );
}
$i = $i % count( $users );
for ( ; $weeks > 0; $weeks-- ) {
	$ts += 86400*7;
	$format = 'F j';
	if ( date( 'Y', $ts ) !== date( 'Y' ) ) {
		$format .= ', Y';
	}
	echo date( $format, $ts ) . ': @' . $users[$i] . PHP_EOL;
	$i = ( $i + 1 ) % count( $users );
}