When working with dates and times in JavaScript, one of the common tasks is calculating the day of the week based on UTC (Coordinated Universal Time). The Date.getUTCDay() method allows us to retrieve the day of the week as opposed to local time, based on universal time standards. This method is especially useful when we want to compare dates universally and independently of specific time zones. It is very practical.
Using this method can be beneficial for various applications, such as recording dates of international events, scheduling cross-timezone activities, or whenever you need to calculate the day of the week based on UTC time, regardless of local variations. Keep in mind that this method only returns the day of the week as a number that starts with 0 for Sunday and continues to 6 for Saturday.
Using Date.getUTCDay() in real-world applications often helps relate scheduling events internationally more accurately than using local time-based date calculations, or that these time values are saved in more structured formats in databases. One advantage of it is minimizing discrepancies related to time zone changes and summer time settings.
Now, with the example below, we will examine how to use this method more closely and explain how it can be implemented in your code.
<script>
// Creating a new date instance
const now = new Date();
// Using the getUTCDay method to get the day of the week based on UTC time
const utcDay = now.getUTCDay();
// Print the result in the console
console.log(utcDay); // Output: a number between 0 and 6 representing the day of the week
</script>Line-by-Line Explanation of the Code
const now = new Date();
This line creates a new instance of the Date class that represents the current date and time.
const utcDay = now.getUTCDay();
This line retrieves the day of the week in the form of a number based on UTC time from the Date instance created.
console.log(utcDay);
This line prints the day of the week, which was retrieved by getUTCDay, to the console.