How to pass multiple parameters to cron job with curl?

I'm running two cron jobs:

This one executes without a problem:

curl -sS http://example.com/cronjob.php?days=1

But this doesn't run at all:

curl -sS http://example.com/cronjob.php?days=1&month=1

Is this because of the ampersand (&)? If yes, how to pass multiple parameters?

Using argv is not an option.