The Date.UTC() function in JavaScript returns the number of milliseconds since the Unix Epoch (January 1, 1970, 00:00:00 UTC) for a specified UTC (Coordinated Universal Time) date and time.

Syntax:

Date.UTC(year, month, day, hours, minutes, seconds, milliseconds);

Parameters:

• year: The full year (e.g., 2024).
• month: The month (0 for January, 11 for December). Note: Months are zero-indexed.
• day (optional): The day of the month (1-31). Default is 1.
• hours (optional): The hour of the day (0-23). Default is 0.
• minutes (optional): The minutes (0-59). Default is 0.
• seconds (optional): The seconds (0-59). Default is 0.
• milliseconds (optional): The milliseconds (0-999). Default is 0.

Returns:

• The number of milliseconds between the Unix Epoch and the given UTC date.

Example 1: Basic Date (Year, Month)

const timestamp = Date.UTC(2024, 9, 22); // October 22, 2024, UTC
console.log(timestamp);

Output:

1729555200000

Explanation:

• Date.UTC(2024, 9, 22) represents October 22, 2024, at 00:00:00 UTC.
• The function returns the timestamp in milliseconds: 1729555200000.

Example 2: Full Date and Time

const timestamp = Date.UTC(2024, 9, 22, 14, 30, 15); // October 22, 2024, 14:30:15 UTC
console.log(timestamp);

Output:

1729607415000

Explanation:

• Date.UTC(2024, 9, 22, 14, 30, 15) represents October 22, 2024, at 14:30:15 UTC.
• The result is 1729607415000 milliseconds.

Example 3: Handling Zero-Indexed Month

const timestamp = Date.UTC(2024, 0, 1); // January 1, 2024
console.log(timestamp);

Output:

1704067200000

Explanation:

• The month is zero-indexed, so 0 corresponds to January.
• Date.UTC(2024, 0, 1) represents January 1, 2024, and returns 1704067200000 milliseconds.

Summary:

• Date.UTC() generates a timestamp for a UTC date, allowing you to specify year, month, day, hours, minutes, seconds, and milliseconds.
• Months are zero-indexed: January is 0, December is 11.
• It returns the number of milliseconds from January 1, 1970 (Unix Epoch) to the given UTC date.