# Time Difference
**URL:** https://discourse.processing.org/t/time-difference/34858
**Category:** Coding Questions
**Created:** [January 27, 2022, 2:28am UTC](https://discourse.processing.org/t/time-difference/34858 "2022-01-27T02:28:11Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Bunnytoes](https://discourse.processing.org/u/Bunnytoes)
#### Post date: [January 27, 2022, 2:28am UTC](https://discourse.processing.org/t/time-difference/34858/1 "2022-01-27T02:28:11Z")
I want to get a change in time, but I don’t know how to do that in processing (in java I know there is Instant.Now but what is there in processing)?
---
### Author:  [@SomeOne](https://discourse.processing.org/u/SomeOne)
#### Post date: [January 27, 2022, 4:59am UTC](https://discourse.processing.org/t/time-difference/34858/2 "2022-01-27T04:59:06Z")
Function [millis()](https://processing.org/reference/millis_.html) tells you how many milliseconds has passed from start of the sketch.
---
### Author:  [@FurryNightShade](https://discourse.processing.org/u/FurryNightShade)
#### Post date: [February 3, 2022, 5:36pm UTC](https://discourse.processing.org/t/time-difference/34858/3 "2022-02-03T17:36:14Z")
There are a number of ways:
- [`System.currentTimeMillis()`](https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html#now--) returns Unix time _(time in miliseconds since January 1st 1970 00:00:00)_
- [`millis()`](https://processing.org/reference/millis_.html) returns time in miliseconds since the start of your sketch
- [`System.nanoTime()`](https://docs.oracle.com/javase/7/docs/api/java/lang/System.html#nanoTime()) returns time in nanoseconds. It is only useful for differences in time.
- [`Instant.now()`](https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html#now--) returns an `Instance` object _(It might be slow since `Instance` is an object and object construction is slow)_
As for me, I prefer to use `System.currentTimeMillis()` and I always have a custom `Stopwatch` class. This is a simple one I just quickly made:
```auto
public final class Stopwatch{
private long lastUpdate;
public Stopwatch(){
this.lastUpdate = System.currentTimeMillis();
}
public long update(){
long time = System.currentTimeMillis();
long delta = this.lastUpdate - time;
this.lastUpdate = time;
return delta;
}
}
```
Also you should know, Processing is just a library for Java. You can still use your `Instant.now()` approach. Nothing changes, but almost everything you write in your .pde files gets wrapped in a class that extends `PApplet`.
---
### Author:  [@Bunnytoes](https://discourse.processing.org/u/Bunnytoes)
#### Post date: [February 4, 2022, 4:15pm UTC](https://discourse.processing.org/t/time-difference/34858/4 "2022-02-04T16:15:45Z")
Hello, thank you for your help, but to still use the Instant.now you have to have set up processing in an IDE and when I did it on intellij it used settings() instead of setup() so I don’t know how easy it would be to write code like that
thanks for the help
---
### Author:  [@Bunnytoes](https://discourse.processing.org/u/Bunnytoes)
#### Post date: [February 4, 2022, 4:17pm UTC](https://discourse.processing.org/t/time-difference/34858/5 "2022-02-04T16:17:12Z")
also could you please put in the whole stopwatch class not just the simple one because that would be very helpful
thanks
---
### Author:  [@FurryNightShade](https://discourse.processing.org/u/FurryNightShade)
#### Post date: [February 4, 2022, 6:52pm UTC](https://discourse.processing.org/t/time-difference/34858/6 "2022-02-04T18:52:32Z")
> [@Bunnytoes](#):
>
> Hello, thank you for your help, but to still use the Instant.now you have to have set up processing in an IDE and when I did it on intellij it used settings() instead of setup() so I don’t know how easy it would be to write code like that
> thanks for the help
When Processing compiles your code (using an executable `processing-java.exe`), all .pde files get combined in one .java file and then edited. All `import` lines are put to the top, everything else is then put in a PApplet extending class. If you write
```auto
void setup(){
size(640, 480);
}
```
and compile it, Processing will output
```auto
public void settings() { size(640, 480); }
```
As an example of a sketch you might make:
Test
├─`Test.pde`
└─`SayHello.pde`
**Test.pde**
```auto
import java.nio.file.Paths;
SayHello a, b, c, d;
void setup(){
size(640, 480, P2D);
surface.setResizable(true);
a = new SayHello("Kate");
b = new SayHello("Thomas");
c = new SayHello("Anna");
d = new SayHello("Ezekiel");
SayHello.say(a);
SayHello.say(a, b);
SayHello.say(a, b, c);
SayHello.say(a, b, c, d);
}
void draw(){
background(23);
}
```
**SayHello.pde**
```auto
final static class SayHello{
private String name;
SayHello(String name){
this.setName(name);
}
public SayHello setName(String name){
this.name = name == null ? "" : name;
return this;
}
public String getName(){
return this.name;
}
@Override public String toString(){
return "Hello " + this.name + "!";
}
public SayHello say(){
System.out.println("Hello " + this.name + "!");
return this;
}
public static void say(SayHello... hellos){
ArrayList valid = new ArrayList();
for(int i = 0; i < hellos.length; i ++){
if(hellos[i] != null) if(!valid.contains(hellos[i])) valid.add(hellos[i]);
}
if(valid.size() == 0) System.out.println("There is noone to say hello to. :(");
else{
String s = "Hello ";
for(int i = 0; i < valid.size(); i ++){
if(i == valid.size() - 1 && valid.size() > 1) s += " and ";
else if(i > 0) s += ", ";
s += valid.get(i).getName();
}
s += ".";
System.out.println(s);
}
}
}
```
When Processing compiles it, it becomes:
`Test`
├─`out`
│ ├─`source`
│ │ ├─`Test.java`
│ ├─`Test.class`
│ ├─`Test§SayHello.class`
├─`Test.pde`
└─`SayHello.pde`
**Test.java**
```auto
import processing.core.*;
import processing.data.*;
import processing.event.*;
import processing.opengl.*;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.ArrayList;
import java.io.File;
import java.io.BufferedReader;
import java.io.PrintWriter;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
public class Test extends PApplet {
SayHello a, b, c, d;
public void setup(){
surface.setResizable(true);
a = new SayHello("Kate");
b = new SayHello("Thomas");
c = new SayHello("Anna");
d = new SayHello("Ezekiel");
SayHello.say(a);
SayHello.say(a, b);
SayHello.say(a, b, c);
SayHello.say(a, b, c, d);
}
public void draw(){
background(23);
}
final static class SayHello{
private String name;
SayHello(String name){
this.setName(name);
}
public SayHello setName(String name){
this.name = name == null ? "" : name;
return this;
}
public String getName(){
return this.name;
}
@Override public String toString(){
return "Hello " + this.name + "!";
}
public SayHello say(){
System.out.println("Hello " + this.name + "!");
return this;
}
public static void say(SayHello... hellos){
ArrayList valid = new ArrayList();
for(int i = 0; i < hellos.length; i ++){
if(hellos[i] != null) if(!valid.contains(hellos[i])) valid.add(hellos[i]);
}
if(valid.size() == 0) System.out.println("There is noone to say hello to. :(");
else{
String s = "Hello ";
for(int i = 0; i < valid.size(); i ++){
if(i == valid.size() - 1 && valid.size() > 1) s += " and ";
else if(i > 0) s += ", ";
s += valid.get(i).getName();
}
s += ".";
System.out.println(s);
}
}
}
public void settings() { size(640, 480, P2D); }
static public void main(String[] passedArgs) {
String[] appletArgs = new String[] { "Test" };
if (passedArgs != null) {
PApplet.main(concat(appletArgs, passedArgs));
} else {
PApplet.main(appletArgs);
}
}
}
```
This is most likely done, so that the code could be then compiled as a regular Java project.
> [@Bunnytoes](#):
>
> also could you please put in the whole stopwatch class not just the simple one because that would be very helpful
> thanks
Sure. I wrote it in pure Java though.
**Stopwatch.java**
```auto
import java.util.ArrayList;
public class Stopwatch {
final private static ArrayList instances = new ArrayList();
private long time, lastUpdated, lastDelta;
private boolean isRunning;
public Stopwatch(){
this.time = 0;
this.lastUpdated = System.currentTimeMillis();
this.isRunning = true;
this.lastDelta = 0;
instances.add(this);
}
public Stopwatch(boolean isRunning){
this.time = 0;
this.lastUpdated = System.currentTimeMillis();
this.isRunning = isRunning;
this.lastDelta = 0;
instances.add(this);
}
public Stopwatch(boolean isRunning, boolean includeInInstanceList){
this.time = 0;
this.lastUpdated = System.currentTimeMillis();
this.isRunning = isRunning;
this.lastDelta = 0;
if(includeInInstanceList) instances.add(this);
}
//Static for all instances in Stopwatch.instances
public static void updateAllInstances(){
for(int i = 0; i < Stopwatch.instances.size(); i ++){
Stopwatch.instances.get(i).update();
}
}
public static void destroyAllInstances(){
for(int i = 0; i < Stopwatch.instances.size(); i ++){
Stopwatch.instances.get(i).destroy();
}
}
public static Stopwatch[] getRunningInstances(){
ArrayList list = new ArrayList();
for(int i = 0; i < Stopwatch.instances.size(); i ++){
Stopwatch instance = Stopwatch.instances.get(i);
if(instance.isRunning()) list.add(instance);
}
Stopwatch[] returnArray = new Stopwatch[list.size()];
for(int i = 0; i < returnArray.length; i ++) returnArray[i] = list.get(i);
return returnArray;
}
public static Stopwatch[] getStoppedInstances(){
ArrayList list = new ArrayList();
for(int i = 0; i < Stopwatch.instances.size(); i ++){
Stopwatch instance = Stopwatch.instances.get(i);
if(instance.isStopped()) list.add(instance);
}
Stopwatch[] returnArray = new Stopwatch[list.size()];
for(int i = 0; i < returnArray.length; i ++) returnArray[i] = list.get(i);
return returnArray;
}
public static Stopwatch[] getPausedInstances(){
ArrayList list = new ArrayList();
for(int i = 0; i < Stopwatch.instances.size(); i ++){
Stopwatch instance = Stopwatch.instances.get(i);
if(instance.isPaused()) list.add(instance);
}
Stopwatch[] returnArray = new Stopwatch[list.size()];
for(int i = 0; i < returnArray.length; i ++) returnArray[i] = list.get(i);
return returnArray;
}
public static Stopwatch[] getNonrunningInstances(){
ArrayList list = new ArrayList();
for(int i = 0; i < Stopwatch.instances.size(); i ++){
Stopwatch instance = Stopwatch.instances.get(i);
if(!instance.isRunning()) list.add(instance);
}
Stopwatch[] returnArray = new Stopwatch[list.size()];
for(int i = 0; i < returnArray.length; i ++) returnArray[i] = list.get(i);
return returnArray;
}
//Removes object from Stopwatch.instances
final public void destroy(){
Stopwatch.instances.remove(this);
}
//Updates Stopwatch
final public synchronized Stopwatch update(){
if(!this.isRunning) return this;
long time = System.currentTimeMillis();
long delta = this.time - this.lastUpdated;
this.lastDelta = delta;
this.time += delta;
this.lastUpdated = time;
return this;
}
//Updates Stopwatch by a specified time
final public synchronized Stopwatch update(long time){
if(!this.isRunning || time <= 0) return this;
long currentTime = System.currentTimeMillis();
long delta = time;
this.lastDelta = delta;
this.time += delta;
this.lastUpdated = currentTime;
return this;
}
final public synchronized Stopwatch update(TimeMeasurement time){
if(!this.isRunning || time == null) return this;
if(time.value <= 0) return this;
long currentTime = System.currentTimeMillis();
long delta = time.value;
this.lastDelta = delta;
this.time += delta;
this.lastUpdated = currentTime;
return this;
}
//Controls
final public synchronized Stopwatch resume(){
if(this.isRunning) return this;
this.isRunning = true;
this.lastUpdated = System.currentTimeMillis();
if(this.time == 0) this.onStart();
else this.onResume();
return this;
}
final public synchronized Stopwatch pause(){
if(!this.isRunning) return this;
long time = System.currentTimeMillis();
this.time += time - this.lastUpdated;
this.isRunning = false;
this.onPause();
return this;
}
final public synchronized Stopwatch stop(){
this.isRunning = false;
this.time = 0;
this.onStop();
return this;
}
//Events
protected void onResume(){}
protected void onStart(){}
protected void onPause(){}
protected void onStop(){}
//Questions about controls
final public boolean isRunning(){
return this.isRunning;
}
final public boolean isPaused(){
return !this.isRunning && this.time != 0;
}
final public boolean isStopped(){
return !this.isRunning && this.time == 0;
}
final public TimeMeasurement getTime(){
return new TimeMeasurement(this.update().time);
}
final public long getTimeValue(){
return this.update().time;
}
final public TimeMeasurement getDelta(){
return new TimeMeasurement(this.lastDelta);
}
final public long getDeltaValue(){
return this.lastDelta;
}
final public Stopwatch copy(){
Stopwatch sw = new Stopwatch();
sw.time = this.time;
sw.lastUpdated = this.lastUpdated;
sw.lastDelta = this.lastDelta;
sw.isRunning = this.isRunning;
if(Stopwatch.instances.contains(this)) Stopwatch.instances.add(this);
return sw;
}
final public Stopwatch copy(boolean includeInInstanceList){
Stopwatch sw = new Stopwatch();
sw.time = this.time;
sw.lastUpdated = this.lastUpdated;
sw.lastDelta = this.lastDelta;
sw.isRunning = this.isRunning;
if(includeInInstanceList) Stopwatch.instances.add(this);
return sw;
}
}
```
**TimeMeasurement.java**
```auto
final public class TimeMeasurement implements Comparable{
final static public TimeMeasurement ZERO = new TimeMeasurement(0);
final static public TimeMeasurement SECOND = new TimeMeasurement(1000);
final static public TimeMeasurement MINUTE = new TimeMeasurement(60000);
final static public TimeMeasurement HOUR = new TimeMeasurement(3600000);
final static public TimeMeasurement DAY = new TimeMeasurement(86400000);
final public long value;
public TimeMeasurement(long value){
this.value = value;
}
public long getMiliseconds(){
return this.value % 1000;
}
public long getSeconds(){
return this.value / TimeMeasurement.SECOND.value % 60;
}
public long getMinutes(){
return this.value / TimeMeasurement.MINUTE.value % 60;
}
public long getHours(){
return this.value / TimeMeasurement.HOUR.value % 60;
}
public long getDays(){
return this.value / TimeMeasurement.DAY.value;
}
public long getTotalMiliseconds(){
return this.value;
}
public long getTotalSeconds(){
return this.value / TimeMeasurement.SECOND.value;
}
public long getTotalMinutes(){
return this.value / TimeMeasurement.MINUTE.value;
}
public long getTotalHours(){
return this.value / TimeMeasurement.HOUR.value;
}
public long getTotalDays(){
return this.value / TimeMeasurement.DAY.value;
}
public TimeMeasurement subtract(TimeMeasurement time){
if(time == null) throw new NullPointerException();
return new TimeMeasurement(this.value - time.value);
}
public TimeMeasurement subtract(long time){
return new TimeMeasurement(this.value - time);
}
public TimeMeasurement add(TimeMeasurement time){
if(time == null) throw new NullPointerException();
return new TimeMeasurement(this.value + time.value);
}
public TimeMeasurement add(long time){
return new TimeMeasurement(this.value + time);
}
public TimeMeasurement difference(TimeMeasurement time){
if(time == null) throw new NullPointerException();
return new TimeMeasurement(Math.abs(this.value + time.value));
}
public TimeMeasurement difference(long time){
return new TimeMeasurement(Math.abs(this.value + time));
}
public int compareTo(TimeMeasurement time){
if(time == null) throw new NullPointerException();
long diff = this.value - time.value;
return diff < 0 ? -1 : (diff > 0 ? 1 : 0);
}
@Override public boolean equals(Object time){
if(time == null) return false;
if(!(time instanceof TimeMeasurement)) return false;
return this.value == ((TimeMeasurement)time).value;
}
}
```
---
### Author:  [@Bunnytoes](https://discourse.processing.org/u/Bunnytoes)
#### Post date: [February 5, 2022, 11:02pm UTC](https://discourse.processing.org/t/time-difference/34858/7 "2022-02-05T23:02:26Z")
Alright, Thanks for the help