How to Get Milliseconds from a Date in Swift

In Swift, working with dates and times can be essential for many applications, and sometimes we need to retrieve milliseconds from a given date. In this article, we will explore various ways to get milliseconds from a Date in Swift.

Understanding Dates in Swift

Before we dive into how to get milliseconds from a Date, let's first understand how Dates are represented in Swift.

In Swift, dates are represented by the Date struct. It represents a specific point in time, independent of any particular calendar or time zone. The Date struct stores a TimeInterval value that represents the number of seconds since January 1, 1970, at 00:00:00 UTC.

Retrieving Milliseconds from a Date

To get milliseconds from a Date in Swift, we first need to convert the date into a Unix timestamp. A Unix timestamp represents the number of seconds since January 1, 1970, at 00:00:00 UTC.

Once we have the Unix timestamp, we can multiply it by 1000 to get the number of milliseconds. Here's an example of how to get the milliseconds from a Date in Swift:

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1let date = Date()
2let milliseconds = Int(date.timeIntervalSince1970 * 1000)
3print(milliseconds)

In the code above, we first create a new instance of Date. We then use the timeIntervalSince1970 property to get the Unix timestamp of the date, which is a TimeInterval value. We multiply the timeIntervalSince1970 value by 1000 to convert it into milliseconds, and then we cast it to an Int.

Using Foundation's DateFormatter

If you need to format a date string that includes milliseconds, you can use Foundation's DateFormatter class. Here's an example of how to use DateFormatter to get a date string that includes milliseconds:

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1let date = Date()
2let formatter = DateFormatter()
3formatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"
4let dateString = formatter.string(from: date)
5print(dateString)

In the code above, we first create a new instance of Date. We then create a new instance of DateFormatter and set its dateFormat property to include milliseconds. Finally, we call the string(from:) method on the formatter to get the date string that includes milliseconds.

Conclusion

In conclusion, getting milliseconds from a Date in Swift is a simple task. We can convert the date into a Unix timestamp and then multiply it by 1000 to get the number of milliseconds. We can also use Foundation's DateFormatter class to format a date string that includes milliseconds. With these tools, we can easily work with dates and times in our Swift applications.