If 15 August 2012 falls on a Thursday, then on which day of the week does 11 June 2013 fall, based on calendar calculations?

Introduction / Context:
This question is about relative calendar computation. You are given the day of the week for 15 August 2012 and asked to determine the weekday on 11 June 2013. Instead of relying on real historical weekday data, you take the given weekday as an assumption and then use the number of days between the two dates to determine the resulting day of the week.

Given Data / Assumptions:
- 15 August 2012 is assumed to be a Thursday.
- We are working within the Gregorian calendar framework.
- We must find the weekday on 11 June 2013.
- The calculation depends only on the difference in days between the two dates, not on their actual historical weekdays.

Concept / Approach:
To find the weekday on 11 June 2013, we calculate the number of days between 15 August 2012 and 11 June 2013. Then we take this number modulo 7 to obtain how many weekdays forward we must move. Finally, we shift the starting weekday, Thursday, forward by that remainder to obtain the target weekday.

Step-by-Step Solution:
Step 1: Count the days remaining in August 2012 from 16 August to 31 August, which gives 16 days.Step 2: Add the days in the months from September 2012 through May 2013: September 30, October 31, November 30, December 31, January 31, February 28 (2013 is not a leap year), March 31, April 30, May 31.Step 3: Sum these month lengths: 30 + 31 + 30 + 31 + 31 + 28 + 31 + 30 + 31 = 273 days.Step 4: Add the first 11 days of June 2013 to reach 11 June, giving 16 + 273 + 11 = 300 days from 15 August 2012 to 11 June 2013.Step 5: Compute 300 modulo 7. Since 7 * 42 = 294, the remainder is 300 - 294 = 6.Step 6: A remainder of 6 means the weekday advances by 6 days from the starting weekday.Step 7: Starting from Thursday, move forward 6 days: Thursday (0), Friday (1), Saturday (2), Sunday (3), Monday (4), Tuesday (5), Wednesday (6).Step 8: Therefore, 11 June 2013 falls on a Wednesday under the given assumption.

Verification / Alternative check:
If you move backward by 1 day instead, you can see that a shift of 6 forward is equivalent to a shift of 1 backward (since 6 ≡ -1 modulo 7). One day before Thursday is Wednesday, which matches the result of the forward counting, confirming that the weekday we found is consistent with modular arithmetic on the weekly cycle.

Why Other Options Are Wrong:
Saturday, Monday, Tuesday and Thursday correspond to remainders of 2, 4, 5 or 0 respectively when treating the day difference modulo 7. None of these match the calculated remainder of 6. Choosing any of them would imply an incorrect day offset between the two dates.

Common Pitfalls:
Students often miscount the number of days in each month or forget whether to include the starting date. Others compute the total days correctly but make errors when reducing modulo 7 or when stepping through the weekdays. To avoid these mistakes, write out each intermediate sum clearly and move carefully through the weekday sequence.

Final Answer:
Under the given assumption, 11 June 2013 falls on a Wednesday.