The bill (which you can read here, it's super short: https://www.congress.gov/bill/117th-congress/senate-bill/623/text https://www.congress.gov/bill/117th-congr

The bill (which you can read here, it's super short: https://www.congress.gov/bill/117th-congress/senate-bill/623/text https://www.congress.gov/bill/117th-congress/senate-bill/623...) adjusts EST/CST/MST/PST etc to be +01:00. If you dig into the bill it's referencing, it defines US timezones based on UTC so this is just adjusting the time +1 hour based on that original bill.