Merge pull request #11 from danielrichman/master

'Fix' POSIXtoHM
Update calc.js
Update index.php
Merge pull request #13 from abrosio/patch-2

Update index.php (see also PR #12 for calc.js)
Merge pull request #12 from abrosio/patch-1

Update calc.js (see also #13 for index.php)
Increase max rates to 20m/s