Just FYI, I'm registering from home where I use Cygwin . . . so uname returns "CYGWIN_NT-6.1-WOW64" and ultimately the response from "date -u..." is not accepted by the registration form. I had to search around the forums to figure out I should replace $(uname) with "Linux".
Hate wasting time on stupid stuff...
But obviously you did eventually figure it out and successfully register. The registration "test" is a successful spam filter.
Welcome to Arch.
This subforum has a number of threads about the the registration process; basically, it works for 95% of people, and of the 5% that have to improvise, only the worthy make it through...
Closing, as this is well covered.