What are quick memory hooks for the two most-used century anchors?

2000s = Tuesday ("Y2K → Twos-day"); 1900s = Wednesday.

• 2000s → Tuesday: the year 2000 doomsday was a Tuesday — think "Y2K, Twosday" (2 = Tuesday's number).
• 1900s → Wednesday: the workhorse anchor for 20th-century dates.

From those two you can reach the others via the 400-year cycle if needed, but almost every birthday or modern date you'll be asked about lives in the 1900s or 2000s, so nail those two first.