Convert from days to milliseconds
JavaDatetime ConversionJava Problem Overview
I want to create a function that will convert the days into milliseconds. The days format is stored as 0.2444, so how to convert this to milliseonds?
Java Solutions
Solution 1 - Java
The best practice for this, in my opinion is:
TimeUnit.DAYS.toMillis(1); // 1 day to milliseconds.
TimeUnit.MINUTES.toMillis(23); // 23 minutes to milliseconds.
TimeUnit.HOURS.toMillis(4); // 4 hours to milliseconds.
TimeUnit.SECONDS.toMillis(96); // 96 seconds to milliseconds.
Solution 2 - Java
In addition to the other answers, there is also the TimeUnit class which allows you to convert one time duration to another. For example, to find out how many milliseconds make up one day:
TimeUnit.MILLISECONDS.convert(1, TimeUnit.DAYS); //gives 86400000
Note that this method takes a long
, so if you have a fraction of a day, you will have to multiply it by the number of milliseconds in one day.
Solution 3 - Java
Won't days * 24 * 60 * 60 * 1000
suffice?
Solution 4 - Java
Its important to mention that once in 4-5 years this method might give a 1 second error, becase of a leap-second (http://www.nist.gov/pml/div688/leapseconds.cfm), and the correct formula for that day would be
(24*60*60 + 1) * 1000
There is a question https://stackoverflow.com/questions/14065355/are-leap-seconds-catered-for-by-calendar and the answer is no.
So, if You're designing super time-dependant software, be careful about this formula.
Solution 5 - Java
24 hours = 86400 seconds = 86400000 milliseconds. Just multiply your number with 86400000.
Solution 6 - Java
public static double toMilliSeconds(double day)
{
return day * 24 * 60 * 60 * 1000;
}
or as long
:
public static long toMilliSeconds(double day)
{
return (long) (day * 24 * 60 * 60 * 1000);
}
Solution 7 - Java
You can use this utility class -
public class DateUtils
{
public static final long SECOND_IN_MILLIS = 1000;
public static final long MINUTE_IN_MILLIS = SECOND_IN_MILLIS * 60;
public static final long HOUR_IN_MILLIS = MINUTE_IN_MILLIS * 60;
public static final long DAY_IN_MILLIS = HOUR_IN_MILLIS * 24;
public static final long WEEK_IN_MILLIS = DAY_IN_MILLIS * 7;
}
If you are working on Android framework then just import
it (also named DateUtils
) under package android.text.format
Solution 8 - Java
int day = 5;
long dayInMilliseconds = day * org.apache.commons.lang.time.DateUtils.MILLIS_PER_DAY