The ride through hell should begin on January 10, 2022

Per ARS 41-1101, 

"A. The legislature shall assemble at the seat of government at twelve o'clock noon on the second Monday of January each year."

In 2022, the second Monday in January 2022 is January 10th, so the Arizona Legislature should be in session/back to working against the interests of all Arizonans.

If they're being consistent (a big caveat with the AZLege; usually the only thing they're consistent about is being nuts), the final day to introduce bills and not have them subject to a 7-bill limit is the close of business on the Thursday of the first week of the session.

House rule 8C (top) and Senate rule 14C (bottom)

There *is* a final day for members of each chamber to introduce bills without the approval of that chamber's Rules Committee.  Each chamber has it own deadline. I think in the House it will be on February 7,2022 and in the Senate it will be on January 31, 2022, but I haven't confirmed those at this point.  Anyway, the deadline will be at the close of business on whatever day (usually, 5 p.m.)