Which date every year is celebrated as United Nations Day to mark the entry into force of the United Nations Charter?

Introduction / Context:
United Nations Day is an important international observance that marks the anniversary of the entry into force of the United Nations Charter. It symbolises the beginning of the modern United Nations system and the global commitment to international peace, security, and cooperation. This question focuses on the exact date on which United Nations Day is celebrated every year, a standard fact in international general knowledge.

Given Data / Assumptions:

• The observance is called United Nations Day, often written as UN Day.
• It is celebrated every year by United Nations member states.
• The options provide different dates spread across the year, some of which are linked with other well known events.
• Only one of these dates is officially connected with United Nations Day.

Concept / Approach:
To answer correctly, learners need to recall when the United Nations Charter came into force after being ratified by key founding countries. The date of this historic event later became the fixed day for United Nations Day. Therefore, remembering the signing or enforcement timeline of the charter helps fix the date in memory. Competitive exams often use this question to test knowledge of international organisations and world history.

Step-by-Step Solution:
Step 1: Recall that the United Nations Charter entered into force in 1945.Step 2: Remember that this happened on 24 October 1945, which is why the same date is celebrated every year.Step 3: United Nations Day therefore falls on 24 October each year and is commemorated with events at the UN headquarters and in member countries.Step 4: Look at the options and identify 24 October among the listed dates.Step 5: Choose 24 October as the correct answer because it matches the historical date of the charter coming into force.

Verification / Alternative check:
Every year around late October, news reports and official UN websites discuss United Nations Day celebrations on 24 October. Many schools and colleges also conduct special functions on this day to introduce students to the role of the UN. Other days such as 7 April or 26 June have their own significance but are not labelled as United Nations Day in this specific sense.

Why Other Options Are Wrong:
7 April: This date is usually associated with World Health Day and not with United Nations Day.

14 November: In India, 14 November is popularly known as Children Day, and it has no direct link with United Nations Day.

27 December: This date is not connected with the founding or charter of the United Nations in standard references.

26 June: This date is associated with the signing of the UN Charter in 1945, but the observance called United Nations Day is fixed on the date of its entry into force, which is 24 October.

Common Pitfalls:
Students sometimes confuse the signing date and the enforcement date of the UN Charter. Because both are historically important, they may mix 26 June with 24 October. Another source of confusion is the large number of UN related days throughout the year. Creating a simple timeline can help: remember that the charter was signed in June but came into force on 24 October, and United Nations Day follows the latter date.

Final Answer:
24 October