iPhone: How to get current milliseconds?

Question

What is the best way to get the current system time milliseconds?

score 330 · Answer 1 · edited Oct 25 '17 at 23:03

330

If you're looking at using this for relative timing (for example for games or animation) I'd rather use CACurrentMediaTime()

double CurrentTime = CACurrentMediaTime();

Which is the recommended way; NSDate draws from the networked synch-clock and will occasionally hiccup when re-synching it against the network.

It returns the current absolute time, in seconds.

If you want only the decimal part (often used when syncing animations),

let ct = CACurrentMediaTime().truncatingRemainder(dividingBy: 1)

edited Oct 25 '17 at 23:03

Stan James

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answered Apr 30 '10 at 05:03

Allan Simonsen

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But it seems to take double the time needed for [[NSDate date] timeIntervalSince1970]. I measured 0.065ms vs. 0.033ms on 15000 calls. – Kay Jun 29 '11 at 21:43
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Note, you'll need to include the Quartz Framework and #import to make this call. – BadPirate Feb 21 '12 at 21:08
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Whoops - thats import #import – BadPirate Feb 21 '12 at 22:41
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For those new to Xcode (like me) "include Quartz Framework" means adding it to the set of libraries in "Link Binary With Libraries". – Gabe Johnson Sep 18 '12 at 17:01
Or, if you're using Xcode 5 and iOS 7: @import QuartzCore.CAAnimation and you don't need to worry about explicitly adding it to the list of libraries. – Jeremy Brooks Dec 21 '13 at 00:53
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If anyone's looking for this in relation to SpriteKit, the 'current time' in SKScene's update method is indeed the CACurrentMediaTime(); – Anthony Mattox Feb 14 '14 at 03:08
it's results in seconds not milliseconds! – user924 Feb 07 '18 at 12:18
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Important: CACurrentMediaTime() is not ticking while device is sleeping! – Pavel Alexeev Jun 20 '18 at 19:43

score 288 · Accepted Answer · edited Sep 07 '15 at 06:15

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[[NSDate date] timeIntervalSince1970];

It returns the number of seconds since epoch as a double. I'm almost sure you can access the milliseconds from the fractional part.

edited Sep 07 '15 at 06:15

Bhavin Bhadani

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answered Dec 11 '08 at 01:39

codelogic

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I've been using this method for a while and came to realise it can return an earlier value when you call it after couple of miliseconds (e.g. call it consecutively and you might not end up with an increasing sequence) – Ege Akpinar Jun 30 '14 at 10:27
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`[NSDate timeIntervalSinceReferenceDate]` is cheaper. (Though it references a different "epoch" -- if you want 1970 add the constant `NSTimeIntervalSince1970`.) – Hot Licks Sep 13 '14 at 00:53
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timeIntervalSince1970 is a instance property and not a static method on NSDate. So one would have to still write NSTimeInterval myInterval = [NSDate date].timeIntervalSince1970 !! – Kris Subramanian Apr 17 '15 at 17:34
@KrisSubramanian There's a corresponding `dateWithTimerIntervalSince1970` class method. – Caleb Sep 17 '15 at 17:39
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for getting into milliseconds CurrentTime = [[NSDate date] timeIntervalSince1970] * 1000; – Mihir Oza Oct 16 '15 at 07:04
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@MihirOza, but multiplying with 1000 won't provide accurate milliseconds. – Satyam Feb 02 '16 at 06:05
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@Satyam actually multiplying with 1000 will give you millisecond precision, the TimeInterval returned by `timeIntervalSince1970` is actually a Double with "sub-millisecond precision" according to the docs. – Incinerator Dec 14 '17 at 14:56

score 100 · Answer 3 · edited Sep 10 '14 at 18:52

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I benchmarked all the other answers on an iPhone 4S and iPad 3 (release builds). CACurrentMediaTime has the least overhead by a small margin. timeIntervalSince1970 is far slower than the others, probably due to NSDate instantiation overhead, though it may not matter for many use cases.

I'd recommend CACurrentMediaTime if you want the least overhead and don't mind adding the Quartz Framework dependency. Or gettimeofday if portability is a priority for you.

iPhone 4S

CACurrentMediaTime: 1.33 µs/call
gettimeofday: 1.38 µs/call
[NSDate timeIntervalSinceReferenceDate]: 1.45 µs/call
CFAbsoluteTimeGetCurrent: 1.48 µs/call
[[NSDate date] timeIntervalSince1970]: 4.93 µs/call

iPad 3

CACurrentMediaTime: 1.25 µs/call
gettimeofday: 1.33 µs/call
CFAbsoluteTimeGetCurrent: 1.34 µs/call
[NSDate timeIntervalSinceReferenceDate]: 1.37 µs/call
[[NSDate date] timeIntervalSince1970]: 3.47 µs/call

edited Sep 10 '14 at 18:52

devios1

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answered Aug 18 '12 at 16:35

darrinm

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+1, While this is obviously very informative and helpful I wouldn't exactly call it great engineering work without seeing some source code ;) – Steven Lu Apr 07 '14 at 08:31
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Beware of this issue though: http://bendodson.com/weblog/2013/01/29/ca-current-media-time/ This clock apparently stops when the device goes to sleep. – mojuba Jul 25 '15 at 01:30
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There is `NSTimeIntervalSince1970` macro which is the fastest. – Ozgur Vatansever Nov 11 '16 at 15:13
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@ozgur `NSTimeIntervalSince1970` is a constant describing the seconds between 1970-01-01 and the "reference date" (i.e. 2001-01-01), so it is always equal to 978307200 – YourMJK Mar 02 '20 at 23:11

Rajan Maheshwari · Answer 4 · 2016-11-30T10:12:21.503

In Swift we can make a function and do as follows

func getCurrentMillis()->Int64{
    return  Int64(NSDate().timeIntervalSince1970 * 1000)
}

var currentTime = getCurrentMillis()

Though its working fine in Swift 3.0 but we can modify and use the Date class instead of NSDate in 3.0

Swift 3.0

func getCurrentMillis()->Int64 {
    return Int64(Date().timeIntervalSince1970 * 1000)
}

var currentTime = getCurrentMillis()

Rajesh Loganathan · Answer 5 · 2019-09-03T05:30:40.617

33

To get milliseconds for current date.

Swift 4+:

func currentTimeInMilliSeconds()-> Int
    {
        let currentDate = Date()
        let since1970 = currentDate.timeIntervalSince1970
        return Int(since1970 * 1000)
    }

edited Sep 03 '19 at 05:30

answered Jul 10 '18 at 07:11

Rajesh Loganathan

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score 31 · Answer 6 · edited Jul 23 '14 at 08:18

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So far I found gettimeofday a good solution on iOS (iPad), when you want to perform some interval evaluation (say, framerate, timing of a rendering frame...) :

#include <sys/time.h>
struct timeval time;
gettimeofday(&time, NULL);
long millis = (time.tv_sec * 1000) + (time.tv_usec / 1000);

edited Jul 23 '14 at 08:18

giampaolo

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answered Oct 25 '11 at 07:23

Tristan Lorach

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I like this too since it's very portable. Note that depending on the OS you might need to use 'long long' instead of a 'long' and likewise cast time.tv_sec to 'long long' before doing the rest of the calculation. – AbePralle Dec 01 '11 at 23:20
static unsigned long getMStime(void) { struct timeval time; gettimeofday(&time, NULL); return (time.tv_sec * 1000) + (time.tv_usec / 1000); } – David H Apr 26 '12 at 13:54
Interestingly this works fine on my iPhone 5S and Mac but returns a wrong value on an iPad 3. – Hyndrix Feb 19 '14 at 15:56
In order to avoid getting negative numbers I had to cast before the math: int64_t result = ((int64_t)tv.tv_sec * 1000) + ((int64_t)tv.tv_usec / 1000); – jason gilbert Jan 18 '15 at 01:48
it return time in -ve – Muhammad Shauket May 13 '16 at 12:22

score 18 · Answer 7 · edited Aug 04 '17 at 15:35

18

Swift 2

let seconds = NSDate().timeIntervalSince1970
let milliseconds = seconds * 1000.0

Swift 3

let currentTimeInMiliseconds = Date().timeIntervalSince1970.milliseconds

edited Aug 04 '17 at 15:35

Tamás Sengel

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answered Jan 18 '16 at 14:39

quemeful

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`TimeInterval` aka `Double` has no milliseconds property. `Date().timeIntervalSince1970 * 1000` – Leo Dabus Feb 06 '19 at 16:02

score 10 · Answer 8 · answered Jun 27 '11 at 23:45

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It may be useful to know about CodeTimestamps, which provide a wrapper around mach-based timing functions. This gives you nanosecond-resolution timing data - 1000000x more precise than milliseconds. Yes, a million times more precise. (The prefixes are milli, micro, nano, each 1000x more precise than the last.) Even if you don't need CodeTimestamps, check out the code (it's open source) to see how they use mach to get the timing data. This would be useful when you need more precision and want a faster method call than the NSDate approach.

http://eng.pulse.me/line-by-line-speed-analysis-for-ios-apps/

answered Jun 27 '11 at 23:45

Tyler

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And you'll probably need a `-fno-objc-arc` if you're using ARC :) – Dan Rosenstark Oct 06 '11 at 20:55
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Mirror: https://web.archive.org/web/20131030113838/http://eng.pulse.me/line-by-line-speed-analysis-for-ios-apps/ – Tomas Andrle Jul 23 '14 at 12:19
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Source code linked from the page is here: https://github.com/tylerneylon/moriarty – Tomas Andrle Jul 23 '14 at 12:19

score 8 · Answer 9 · edited Aug 27 '15 at 20:44

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// Timestamp after converting to milliseconds.

NSString * timeInMS = [NSString stringWithFormat:@"%lld", [@(floor([date timeIntervalSince1970] * 1000)) longLongValue]];

edited Aug 27 '15 at 20:44

Victor Sigler

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answered Sep 24 '14 at 12:28

Fatima Arshad

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score 6 · Answer 10 · answered May 11 '13 at 09:38

I needed a NSNumber object containing the exact result of [[NSDate date] timeIntervalSince1970]. Since this function was called many times and I didn't really need to create an NSDate object, performance was not great.

So to get the format that the original function was giving me, try this:

#include <sys/time.h>
struct timeval tv;
gettimeofday(&tv,NULL);
double perciseTimeStamp = tv.tv_sec + tv.tv_usec * 0.000001;

Which should give you the exact same result as [[NSDate date] timeIntervalSince1970]

score 5 · Answer 11 · edited Jun 20 '20 at 09:12

CFAbsoluteTimeGetCurrent()

Absolute time is measured in seconds relative to the absolute reference date of Jan 1 2001 00:00:00 GMT. A positive value represents a date after the reference date, a negative value represents a date before it. For example, the absolute time -32940326 is equivalent to December 16th, 1999 at 17:54:34. Repeated calls to this function do not guarantee monotonically increasing results. The system time may decrease due to synchronization with external time references or due to an explicit user change of the clock.

RenniePet · Answer 12 · 2017-03-06T08:18:56.900

This is basically the same answer as posted by @TristanLorach, just recoded for Swift 3:

   /// Method to get Unix-style time (Java variant), i.e., time since 1970 in milliseconds. This 
   /// copied from here: http://stackoverflow.com/a/24655601/253938 and here:
   /// http://stackoverflow.com/a/7885923/253938
   /// (This should give good performance according to this: 
   ///  http://stackoverflow.com/a/12020300/253938 )
   ///
   /// Note that it is possible that multiple calls to this method and computing the difference may 
   /// occasionally give problematic results, like an apparently negative interval or a major jump 
   /// forward in time. This is because system time occasionally gets updated due to synchronization 
   /// with a time source on the network (maybe "leap second"), or user setting the clock.
   public static func currentTimeMillis() -> Int64 {
      var darwinTime : timeval = timeval(tv_sec: 0, tv_usec: 0)
      gettimeofday(&darwinTime, nil)
      return (Int64(darwinTime.tv_sec) * 1000) + Int64(darwinTime.tv_usec / 1000)
   }

ΩlostA · Answer 13 · 2016-02-02T18:20:34.213

Try this :

NSDate * timestamp = [NSDate dateWithTimeIntervalSince1970:[[NSDate date] timeIntervalSince1970]];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"YYYY-MM-dd HH:mm:ss.SSS"];

NSString *newDateString = [dateFormatter stringFromDate:timestamp];
timestamp = (NSDate*)newDateString;

In this example, dateWithTimeIntervalSince1970 is used in combination of the formatter @"YYYY-MM-dd HH:mm:ss.SSS" that will return the date with year, month, day and the time with hours, minutes, seconds, and milliseconds. See the example : "2015-12-02 04:43:15.008". I used the NSString to be sure that the format will be has written before.

lazyTank · Answer 14 · 2019-04-25T07:21:34.910

3

let timeInMiliSecDate = Date()
let timeInMiliSec = Int (timeInMiliSecDate.timeIntervalSince1970 * 1000)
print(timeInMiliSec)

edited Apr 25 '19 at 07:21

answered Apr 25 '19 at 07:12

lazyTank

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Please add some explanation to your code such that others can learn from it - especially if you post an answer to a question that already has a lot of upvoted answers – Nico Haase Apr 25 '19 at 07:38

score 2 · Answer 15 · answered Apr 07 '18 at 03:08

2

 func currentmicrotimeTimeMillis() -> Int64{
let nowDoublevaluseis = NSDate().timeIntervalSince1970
return Int64(nowDoublevaluseis*1000)

}

answered Apr 07 '18 at 03:08

Softlabsindia

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score 1 · Answer 16 · answered Jan 13 '16 at 19:46

1

This is what I used for Swift

var date = NSDate()
let currentTime = Int64(date.timeIntervalSince1970 * 1000)

print("Time in milliseconds is \(currentTime)")

used this site to verify accuracy http://currentmillis.com/

answered Jan 13 '16 at 19:46

DG7

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score 1 · Answer 17 · answered Jan 11 '18 at 11:31

NSTimeInterval time = ([[NSDate date] timeIntervalSince1970]); //double
long digits = (long)time; //first 10 digits        
int decimalDigits = (int)(fmod(time, 1) * 1000); //3 missing digits
/*** long ***/
long timestamp = (digits * 1000) + decimalDigits;
/*** string ***/
NSString *timestampString = [NSString stringWithFormat:@"%ld%03d",digits ,decimalDigits];

score 0 · Answer 18 · edited Jun 25 '12 at 13:34

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[NSDate timeIntervalSinceReferenceDate] is another option, if you don't want to include the Quartz framework. It returns a double, representing seconds.

edited Jun 25 '12 at 13:34

answered Apr 05 '11 at 01:33

Chris

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iPhone: How to get current milliseconds?

18 Answers18

CFAbsoluteTimeGetCurrent()

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