What was the day of the week on 17th June, 1998?

Goal

• Find the day of the week on 17 June 1998.

Method: Doomsday Algorithm (concise, reliable)

1. Century anchor
   For 1900s, the anchor day = Wednesday.

2. Year part (98)
   a = ⌊98/12⌋ = 8b = 98 mod 12 = 2c = ⌊b/4⌋ = 0Doomsday shift = a + b + c = 8 + 2 + 0 = 10 ≡ 3 (mod 7)Year's doomsday = Wednesday + 3 = Saturday.

3. Use a known doomsday date in June
   In non-leap years, 6/6 is a doomsday ⇒ 06 June 1998 was Saturday.17 June is 11 days after 6 June: 11 ≡ 4 (mod 7).Saturday + 4 = Wednesday.

Final Answer
17 June 1998 was Wednesday.