Historical clue formulations

• What the 7 may mean in 7/11 — 2026-01-04
• Part of the calendar named for Caesar — 2020-03-24
• National Hot Dog Month — 2019-02-12
• Bastille Day's month — 2018-12-17
• What the beginnings of 17-, 25-, 40- and 52-Across are each a fourth of, phonetically — 2017-07-04
• Canada Day starts it — 1998-02-05