Horizontal sundial calculations

sub postfix:<°> ($a) { $a * pi / 180 } # degrees to radians
sub postfix:<®> ($a) { $a * 180 / pi } # radians to degrees

my $latitude  = prompt 'Enter latitude       => ';
my $longitude = prompt 'Enter longitude      => ';
my $meridian  = prompt 'Enter legal meridian => ';

my $lat_sin = sin( $latitude° );
say 'Sine of latitude: ', $lat_sin.fmt("%.4f"); 
say 'Longitude offset: ', my $offset = $meridian - $longitude;
say '=' x 48;
say ' Hour  : Sun hour angle° : Dial hour line angle°'; 

for -6 .. 6 -> $hour {
    my $sun_deg  = $hour * 15 + $offset;
    my $line_deg = atan2( ( sin($sun_deg°) * $lat_sin ), cos($sun_deg°) )®;
    printf "%2d %s      %7.3f             %7.3f\n",
    ($hour + 12) % 12 || 12, ($hour < 0 ?? 'AM' !! 'PM'), $sun_deg, $line_deg;
}

Output:

Enter latitude       => -4.95
Enter longitude      => -150.5
Enter legal meridian => -150
Sine of latitude: -0.0863
Longitude offset: 0.5
================================================
 Hour  : Sun hour angle° : Dial hour line angle°
 6 AM      -89.500              84.225
 7 AM      -74.500              17.283
 8 AM      -59.500               8.334
 9 AM      -44.500               4.847
10 AM      -29.500               2.795
11 AM      -14.500               1.278
12 PM        0.500              -0.043
 1 PM       15.500              -1.371
 2 PM       30.500              -2.910
 3 PM       45.500              -5.018
 4 PM       60.500              -8.671
 5 PM       75.500             -18.451
 6 PM       90.500             -95.775