I won’t start preparing returns til 2/1... later, if I can get away with it... between late tax law changes (generally the extenders), and the perennial software issues, it’s a lot less stressful to wait... not sure how (or why) anyone would prepare 1040s before information returns are issued... a sure recipe for amendments.  I enjoyed the 7/15 deadline so much last year that I’m planning on putting at least 40% on extension whether they like it or not... 

As for Biden tax law changes, they can’t realistically happen until TY 2021(at the earliest).