You can find live footage for both of these hearings here. The Senate hearing will begin around 6 a.m. PT 8/21, and the House hearing will begin around 7 a.m. PT 8/24.
Senate:
The Senate holds the first congressional hearings with Postmaster General Louis DeJoy as complaints about slow mail delivery pile up. Democrats worry that DeJoy's cost-cutting measures could also throw a wrench in increased voting by mail this fall.
House:
A House committee will grill Postmaster General Louis DeJoy over whether there is any political motivation behind recent service cuts at the U.S. Postal Service right as the agency expects to handle tens of millions of mail in ballots this fall.