Using the standard Gregorian calendar, on which day of the week did 2nd January 1901 fall?

Introduction / Context:
Day-of-week problems for historical dates are classic in calendar aptitude. A common strategy is to use a known reference date and then count the total number of days (and thus weekday shifts) between the reference and the target date. Here, we want the weekday on 2 January 1901 using known information about 1900 and 1901.

Given Data / Assumptions:

The Gregorian calendar is used.
A well-known reference is that 1 January 1900 was a Monday (a standard fact used in many calendar problems).
Year 1900 is not a leap year because it is divisible by 100 but not by 400.
We need the weekday on 2 January 1901.

Concept / Approach:
First, we find the weekday of 1 January 1901 by taking into account the number of days in the year 1900 and the weekday shift that results. Then, using that weekday, we move forward by one day to find the weekday of 2 January 1901. Since 1900 is a common year with 365 days, the starting weekday for the next year shifts by exactly one day.

Step-by-Step Solution:
Step 1: Confirm the type of year 1900. 1900 is divisible by 100 but not by 400, so it is a common year with 365 days. Step 2: Use the known reference. 1 January 1900 is taken as a Monday. Step 3: Determine the weekday of 1 January 1901. A common year has 365 days, which is 52 weeks and 1 extra day. Therefore, the weekday of 1 January of the next year shifts by 1 day. So, 1 January 1901 is one weekday after Monday, i.e., Tuesday. Step 4: Find the weekday of 2 January 1901. 2 January 1901 is one day after 1 January 1901. So, the weekday moves one more day forward: Tuesday → Wednesday. Therefore, 2 January 1901 was a Wednesday.

Verification / Alternative check:
A direct formula such as Zeller’s congruence also confirms that 2 January 1901 falls on a Wednesday, but for aptitude examinations, using a known reference date and common-year shifts is usually faster and easier to remember. The two-step shift (first across the year 1900, then across one more day) reliably produces Wednesday as the final answer.

Why Other Options Are Wrong:
Monday would have been 1 January 1900, not 2 January 1901. Tuesday fits 1 January 1901, but the question asks for the 2nd, which is one day later. Thursday is one day after Wednesday and would require an extra day shift that is not supported by the calendar arithmetic.

Common Pitfalls:
Some learners mistakenly treat 1900 as a leap year and shift by 2 days instead of 1 when moving to 1901, which would produce the wrong weekday. Others may forget to add the extra day when going from 1 January to 2 January 1901. Always verify whether century years are leap years by checking divisibility by 400, and carefully handle each day shift step by step.

Final Answer:
2 January 1901 fell on a Wednesday.