Beeminder Road utilities.

function insert_point( $road, $point )
{
    // add 7 hours to the time so we're in the right timezone.
    // you'll need to change this to match your timezone.
    $seven_hours = 7 * 60 * 60;
    $point[0] = $point[0] + $seven_hours;

    // Find the right place to put it
    $index = find_right_place( $road, $point[0] );
    array_splice( $road, $index, 0, array($point) );
    return $road;
}

function find_right_place( $road, $timestamp )
{
    for( $i = 0; $i < sizeof( $road ) ; $i++ ) {
        if( $road[$i][0] > $timestamp ) {
            return $i;
        }
    }
    return null;
}

function delete_point( $road, $index )
{
    array_splice( $road, $index );
    return $road;
}

function pretty_road_string( $roaddata, $date_format = "Y-m-d" )
{
    $seven_hours = 7 * 60 * 60;
    $string = "";
    $i =0;
    foreach( $roaddata as &$segment ) {
        $segment[0]= date( $date_format, $segment[0] - $seven_hours );
        $string .= sprintf( "%d: [%s,%s,%s]\n", 
            $i++,
            ornull( $segment[0]),
            ornull( $segment[1]),
            ornull( $segment[2])
        );
    }
    return $string;
}

function ornull( $data )
{
    return is_null( $data ) ? 'null' : $data;
}