How Can I Calculate the Difference Between Two Dates in Android?

Calculating the Difference Between Dates in Android

Determining the difference between two dates in Java and Android is a common task for many applications. In this article, we will explore different approaches for finding the difference in days between a current date and a specific date in the format "yyyy/mm/dd."

Approximating the Difference

A simple method for approximating the difference between two dates is to convert the dates to milliseconds using the getTimeInMillis() method of the Calendar class. Subtracting the milliseconds of the earlier date from the milliseconds of the later date and dividing the result by the number of milliseconds in a day (86400000) gives us an approximate number of days.

long days = (today.getTimeInMillis() - thatDay.getTimeInMillis()) / (24 * 60 * 60 * 1000);

Parsing a String-Formatted Date

To calculate the difference between a current date and a date stored as a string in the format "yyyy/mm/dd," we can use the SimpleDateFormat class to parse the string and create a Date object. The Calendar class can then be used to obtain the numeric values of the date components.

String strThatDay = "1985/08/25";
SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
Date d = formatter.parse(strThatDay);
Calendar thatDay = Calendar.getInstance();
thatDay.setTime(d);

Using JodaTime for Precision

For more precise and reliable date calculations, it is recommended to use a third-party library such as JodaTime. JodaTime provides a comprehensive set of methods for manipulating and comparing dates.

DateTime startDate = new DateTime(2010, 8, 25, 0, 0);
DateTime today = new DateTime();
Days days = Days.daysBetween(startDate, today);

The above is the detailed content of How Can I Calculate the Difference Between Two Dates in Android?. For more information, please follow other related articles on the PHP Chinese website!