Historical clue formulations

• When many businesses open — 2023-09-21
• When a prime-time drama might air — 2022-02-20
• When 13-Across aired for most of its run — 2020-08-23
• When many workdays begin — 2020-03-13
• When many start the workday — 2016-04-17
• When many stores open — 2007-11-07