Castsequence question

[MiRai]

I noticed a lot of people using things like 1,2,3, Spell Name in Castsequences now. Or some people use all zeros. Do these take the place of what commas used to do?

Yup.

If so how many zeros/numbers does it take to = one second.

The answer is dependent on how fast you spam your keys and everyone's macro is most likely going to be different.