devtrackers.gg
I was generally under that impression too at first.
However "Tuesday" and "Wednesday" are not as easy to typo as "21st" and "22nd"
So I got no clue lad.
“Available” means you can download the 5.5 update onto your devices. Go to the App Store or the Riot client and you can download the 5.5 patch right now.
“Go live” means the content from that patch will be playable. You can’t do that right now even though the patch is available to update to. You will be able to tomorrow, Wednesday at around 10am.