Using standard Gregorian calendar calculations, what was the day of the week on 16 July 1776?

Introduction / Context:
This question asks for the weekday corresponding to a specific historical date, 16 July 1776. Calendar based aptitude problems like this one test your understanding of how the Gregorian calendar works and your ability to apply systematic methods such as the odd days method or Zellers congruence to find the day of the week for any given date.

Given Data / Assumptions:
- We are using the standard Gregorian calendar.
- The date is 16 July 1776.
- We must find which weekday (Monday, Tuesday, and so on) corresponds to this date.
- No intermediate reference date is provided in the question, so you can either rely on a known result or apply a formula based method.

Concept / Approach:
There are two broad approaches for such historical date calculations:
1. Memorisation of a few anchor dates with known weekdays and using them to compute other dates.
2. Application of a formula like Zellers congruence, or the odd days method, where you represent the date numerically and compute a value modulo 7 to obtain the weekday index.
In exams, having some well practiced methods greatly speeds up these computations.

Step-by-Step Solution:
Step 1: Represent the date as day = 16, month = July, year = 1776.Step 2: Convert the month and year into the codes required by your chosen method (for example, Zellers congruence uses month codes and century codes).Step 3: Add the day, month code, year code and century adjustment, then account for leap years up to that date.Step 4: Reduce the final sum modulo 7 to obtain a number from 0 to 6, corresponding to days from Sunday through Saturday or Monday through Sunday depending on the convention used.Step 5: When you carry out this calculation accurately for 16 July 1776, the result corresponds to Tuesday.Step 6: Therefore, the day of the week on 16 July 1776 was Tuesday.

Verification / Alternative check:
As an alternative check, you can cross verify using a different anchor date near 1776 whose weekday is known, then count forward or backward by complete weeks and additional days. When done correctly, both approaches should agree on Tuesday as the weekday for 16 July 1776. This cross checking helps confirm that no mistakes were made in the modular arithmetic or in counting leap years.

Why Other Options Are Wrong:
Monday, Wednesday, Friday and Saturday are all one or more days away from Tuesday. Any small error in the calculation of leap years or in the modulo 7 operation can lead to one of these incorrect alternatives, which is why they are good distractors in a multiple choice setting.

Common Pitfalls:
Common issues include forgetting that century years are not leap years unless divisible by 400, misapplying month codes, or using the wrong starting convention for the weekday index. Using two independent methods or at least checking the arithmetic carefully is the best way to avoid these errors.

Final Answer:
The day of the week on 16 July 1776 was Tuesday.