NSDate timeIntervalSince1970在Swift中不起作用？

Question

I am doing this in swift:

let date = NSDate(timeIntervalSince1970: 1432233446145.0)
println("date is \(date)")

The log gives me this:

 date is 47355-09-02 23:55:45 +0000

Then I try to get an interval back out just for testing:

let tI = expirationDate.timeIntervalSinceDate(date)
println("tI = \(tI)")

I get:

tI = 0.0

What am I doing wrong? I can seem to make the timeIntervalSince1970 call work properly. Is there any known issued with that in Swift, or am I missing something here?

Answer 1

1432233446145 most probably is a time interval given in milliseconds :

let date = NSDate(timeIntervalSince1970: 1432233446145.0/1000.0)
print("date is \(date)")
// date is 2015-05-21 18:37:26 +0000

Swift 3 and later:

let date = Date(timeIntervalSince1970: 1432233446145.0/1000.0)

Answer 2

I think your timestamp is incorrect. This results in your date being september 2nd, 47355.

If I use the following I get the date for (right about) now:

let date = NSDate(timeIntervalSince1970: 1431024488)
println("date is \(date)")
// "date is 2015-05-07 18:48:08 +0000"

The printed date is not a localized timestamp, so you'll have to do some localization of your own I suppose. An example:

let formatter = NSDateFormatter()
formatter.dateFormat = "dd-MM-yyyy HH:mm:ss"
println("formatted date is \(formatter.stringFromDate(date))")
// "formatted date is 07-05-2015 20:48:08"

And for completeness I also checked with an expiration date that's 1100 seconds larger than the initial date :

let expirationDate = NSDate(timeIntervalSince1970: 1431025588)
let diff = expirationDate.timeIntervalSinceDate(date)
println("expires in: \(diff)")
// "expires in: 1100.0"

So, the timeIntervalSince1970 seems to work fine, I think your interval was just not what you wanted it to be.

Answer 3

From your code and the log content follows:

date.isEqual(expirationDate)

--> Your stuff has just expired :-).