On which date is United Nations Day officially celebrated every year to mark the coming into force of the UN Charter?

Introduction / Context:
United Nations Day is observed around the world to commemorate the entry into force of the UN Charter and to highlight the role of the United Nations in promoting peace, development and human rights. Knowing the exact date is a common static general knowledge requirement for exams dealing with international organisations and important days.

Given Data / Assumptions:

• The event is United Nations Day.
• The options include 24 October, 24 September, 26 June and 8 August.
• The question asks for the official date of the annual celebration.
• We assume the standard UN calendar of observances.

Concept / Approach:
United Nations Day is celebrated on 24 October each year. This date marks the day in 1945 when the UN Charter came into force after ratification by the required number of states. The Charter itself was signed earlier on 26 June 1945, which is another frequently asked date, but the official UN Day uses the October date.

Step-by-Step Solution:
Step 1: Recall that the UN Charter was signed on 26 June 1945 in San Francisco but became effective later in the year.Step 2: Remember that United Nations Day is tied to the Charter coming into force, not just its signing.Step 3: The Charter entered into force on 24 October 1945, and this date is observed every year as UN Day.Step 4: Among the options, “24 October” matches this historical fact.Step 5: Therefore, select 24 October as the correct answer.

Verification / Alternative check:
Many school calendars and international organisations list 24 October as UN Day, and events such as speeches and exhibitions are arranged around this date. Moreover, the UN itself refers to 24 October as United Nations Day, confirming that this is the correct choice and not the date of signing.

Why Other Options Are Wrong:
24 September: Not associated with the founding of the United Nations.

26 June: This is the date on which the UN Charter was signed, but the question asks about United Nations Day, which marks the Charter coming into force.

8 August: Has no direct link to the creation or charter of the United Nations in the context of this question.

Common Pitfalls:
A common confusion is between the signing date (26 June) and the date the Charter took effect (24 October). Candidates may mistakenly select 26 June because it is linked to the San Francisco Conference. To avoid this, remember that United Nations Day always falls in late October, not June.

Final Answer:
United Nations Day is celebrated each year on 24 October.