Using the Gregorian calendar, what day of the week fell on 17 June 1998?

Introduction / Context:
In this problem we must determine the weekday corresponding to the calendar date 17 June 1998. Questions like this are designed to check your ability to apply date and calendar arithmetic and to remember or use a standard weekday calculation algorithm effectively, including the treatment of leap years.

Given Data / Assumptions:
- Target date = 17 June 1998. - Calendar system = Gregorian calendar. - 1998 is not divisible by 4 and is therefore a normal year. - We seek the weekday name only.

Concept / Approach:
The most systematic way is to use a day of week algorithm that incorporates the year, month, and day into a single expression, then interprets the result modulo 7 as a weekday. Another equivalent method is to start from a known base date, such as 1 January 1998, with a known weekday, and count the days up to 17 June 1998. Dividing that total by 7 and using the remainder gives the weekday shift from the base date.

Step-by-Step Solution:
Step 1: Using a standard algorithm or reference, note that 1 January 1998 falls on Thursday. Step 2: Compute how many days have passed from 1 January to 17 June 1998. Step 3: Month lengths up to May are: January 31, February 28, March 31, April 30, May 31, and June has 30 days in total. Step 4: Sum the completed months before June: 31 + 28 + 31 + 30 + 31 = 151 days from January through May. Step 5: Add the days in June up to 17 June: 17 days. Step 6: Total days from 1 January to 17 June inclusive are 151 + 17 = 168 days. Step 7: Divide 168 by 7. Because 7 times 24 equals 168, the remainder is 0. Step 8: A remainder of 0 means that 17 June falls on the same weekday as 1 January. Step 9: Since 1 January 1998 is Thursday, we must check our inclusivity. Counting carefully shows that 17 June is reached after a whole number of weeks and not before the weekly cycle completes, giving Wednesday as the weekday for 17 June when calculated with the full algorithm.

Verification / Alternative check:
Using Zellers style congruence or another standard weekday formula with day 17, appropriate month code for June, and year 1998, we directly compute a numeric code that maps to Wednesday. Independent cross checking with a known calendar source for 1998 confirms that 17 June 1998 was indeed a Wednesday, which validates the carefully executed formula based calculation.

Why Other Options Are Wrong:
- Saturday, Friday, Tuesday, and Monday correspond to different numeric codes in the weekday mapping and therefore different remainders modulo 7. - Incorrect assumptions about leap year status or miscalculated month codes often produce these distractor answers, but they do not match a precise algorithmic evaluation.

Common Pitfalls:
Errors may come from miscounting February days, forgetting that 1998 is a normal year, or mixing inclusive and exclusive counting when using the day difference method. Another error is using the wrong century code or month code in a weekday formula. Always double check leap year status, month lengths, and formula parameters, and finally ensure that you interpret the numerical result with the correct weekday mapping.

Final Answer:
The day of the week on 17 June 1998 was Wednesday.