United Nations Day (UN Day) is celebrated globally on which date each year to mark the coming into force of the UN Charter?

Introduction / Context:
United Nations Day, often abbreviated as UN Day, is an annual observance that marks the entry into force of the United Nations Charter and symbolises the founding of the United Nations. It is a key date in international relations and global history. This question asks learners to identify the exact date on which UN Day is celebrated every year.

Given Data / Assumptions:

• The observance is United Nations Day (UN Day).
• The day commemorates the coming into force of the UN Charter.
• The options list several dates across different months, including dates that are significant for other events.
• Only one date is officially recognised as UN Day.

Concept / Approach:
The key fact is that the UN Charter entered into force on 24 October 1945. This date was later chosen to be celebrated every year as United Nations Day. While 26 June is important as the signing date of the charter, it is 24 October that is used as the symbolic birthday of the United Nations. Examinations commonly test whether candidates can distinguish between the signing date and the entry into force date.

Step-by-Step Solution:
Step 1: Recall that the UN Charter was signed on 26 June 1945 but did not come into force on that day.Step 2: Remember that the charter came into force after ratification, on 24 October 1945.Step 3: United Nations Day is tied to this entry into force date, not the signing date.Step 4: Look at the options and identify 24 October as option A.Step 5: Choose 24 October as the correct answer.

Verification / Alternative check:
Each year on 24 October, the United Nations and its member states hold events, cultural programmes, and discussions to mark United Nations Day. Official calendars, school textbooks, and news reports all refer to 24 October as UN Day. No comparable pattern exists for 24 September, 15 May, or 10 December in relation to this specific observance, while 26 June remains associated with the signing of the charter rather than the annual UN Day celebration.

Why Other Options Are Wrong:
24 September: This date is not associated with the founding or charter of the United Nations in standard general knowledge.

26 June: This is the date on which the UN Charter was signed, but UN Day is celebrated on the date it entered into force, which is 24 October.

15 May: This date does not match any major UN founding related observance.

10 December: This date is celebrated as Human Rights Day, associated with the Universal Declaration of Human Rights, not as UN Day.

Common Pitfalls:
The main confusion is between 26 June and 24 October because both dates are linked to the UN Charter. Many students remember that the charter was signed on 26 June and mistakenly choose this as UN Day. To avoid this error, it is useful to remember the sequence: the charter was signed in June but came into force in October, and the annual UN Day honours the latter event.

Final Answer:
24 October