How to convert nanoseconds of uptime into a readable date time format

Question

I have extracted accerometer data from a android wearable. While looking at the data i realised the timestamp is not unix covertable. After research i saw the timestamp was actually nanoseconds in uptime. My question is the same as Accelerometer SensorEvent timestamp . However due to me not knowing Java i dont know how convert it using the solutions provided. Is there any python ways i can convert the nanoseconds in uptime into a readable date time format? An example of the timestamp would be "45900482044637".

Answer 1

tl;dr

Duration.ofNanos ( 45_900_482_044_637L )

PT12H45M0.482044637S

java.time

Java 8 and later has a Duration class for this purpose, as part of the new java.time framework (see Tutorial ). These new classes have nanosecond resolution (nine decimal places in fractional second). A Duration represents a span of time as a number of hours, minutes, and seconds.

Android currently does not use Java 8 technology, but there is a back-port of java.time to Java 6 & 7. Further adapted to Android in the ThreeTenABP project.

Note the L appended to numeric literal for a long . Also, underscores make lengthy numbers easier for humans to decipher.

long input = 45_900_482_044_637L;  

Let's convert that number to a Duration object.

Duration duration = Duration.ofNanos ( input );

When we generate a String representation of that Duration object, we get a String formatted using the ISO 8601 standard. That standard uses the pattern PnYnMnDTnHnMnS where the P marks the beginning and the T separates years-months-days from the hours-minutes-seconds.

    System.out.println ( "duration: " + duration );

The answer is twelve hours, forty-five minutes, and a fraction of a second.

duration: PT12H45M0.482044637S

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About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date , Calendar , & SimpleDateFormat .

The Joda-Time project, now in maintenance mode , advises migration to the java.time classes.

To learn more, see the Oracle Tutorial . And search Stack Overflow for many examples and explanations. Specification is JSR 310 .

Where to obtain the java.time classes?

• Java SE 8 , Java SE 9 , and later
  • Built-in.
  • Part of the standard Java API with a bundled implementation.
  • Java 9 adds some minor features and fixes.
• Java SE 6 and Java SE 7
  • Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport .
• Android
  • Later versions of Android bundle implementations of the java.time classes.
  • For earlier Android, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP… .

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval , YearWeek , YearQuarter , and more .

Answer 2

To get the uptime in human-readable format in Python:

>>> from datetime import timedelta
>>> ns = 45900482044637
>>> print(timedelta(microseconds=round(ns, -3) // 1000))
12:45:00.482045

Answer 3

Use:

long millis = TimeUnit.MILLISECONDS.convert(nanosecond, TimeUnit.NANOSECONDS);
Date date = new Date(millis );
DateFormat formatter = new SimpleDateFormat("yyyy/MM/dd hh:mm aaa");
String dateFormatted = formatter.format(date);