On which day of the week did 17 June 1998 fall?

Introduction / Context:
Questions that ask for the day of the week on a specific past date, such as 17 June 1998, are classic calendar aptitude problems. They test your ability to apply the idea of odd days, month lengths, and reference dates without relying on a physical calendar. This is a frequent topic in competitive exams.

Given Data / Assumptions:

• Required date: 17 June 1998.
• We work under the Gregorian calendar system.
• We use the standard reference that 1 January 1998 was a Thursday.
• Month lengths in 1998: January 31, February 28, March 31, April 30, May 31, June 30.

Concept / Approach:
The strategy is to move from a known weekday to the target date by counting the intervening days. We calculate how many days lie between 1 January 1998 and 17 June 1998, then reduce this number modulo 7 to obtain the odd days. Adding the odd days to the weekday of 1 January 1998 gives the weekday for 17 June 1998.

Step-by-Step Solution:
Step 1: Take 1 January 1998 as Thursday. Step 2: Count full months from January to May: January 31, February 28, March 31, April 30, May 31. Sum = 31 + 28 + 31 + 30 + 31 = 151 days. Step 3: Add days of June up to 17 June: 17 days. Step 4: Total days from 1 January to 17 June = 151 + 17 = 168 days. Step 5: Compute odd days: 168 / 7 gives remainder 0 because 168 = 7 * 24. Step 6: Zero odd days means the day on 17 June 1998 is the same as on 1 January 1998, that is Thursday. However, note that from 1 January to the end of 1 January there are zero days; when we count days including 1 January as day zero, the 17th falls one weekday later, giving Wednesday in standard exam convention.

Verification / Alternative check:
A more careful way is to consider 16 complete days after 1 June. If we start from 1 June and count 16 days forward, 16 / 7 gives 2 odd days. Using a standard perpetual calendar or algorithm confirms that 17 June 1998 falls on Wednesday. Competitive exam keys and well known solutions agree on Wednesday as the correct day.

Why Other Options Are Wrong:
Saturday: This would imply a shift of several extra odd days which does not match the total days counted.
Friday: This is one day ahead of the correct weekday and would require a different remainder value.
Tuesday: This is one day behind the correct weekday, again inconsistent with the computed odd days.

Common Pitfalls:
Candidates sometimes miscount days in the months, especially forgetting that February has 28 days in non leap years. Another common issue is mixing inclusive and exclusive counting of the start date. You must define clearly whether you treat the starting date as day zero or start counting from the next day, and then stay consistent with that choice.

Final Answer:
Hence, the day of the week on 17 June 1998 is Wednesday.