Objective-C: help me convert a timestamp to a formatted date/time

Question

I'm really struggling to convert this timestamp to a nice formatted date string.

Here's the timestamp: "1316625985"

And here's the function I've made:

-(NSString*)timestamp2date:(NSString*)timestamp{
    NSString * timeStampString =timestamp;
    //[timeStampString stringByAppendingString:@"000"];   //convert to ms
    NSTimeInterval _interval=[timeStampString doubleValue];
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:_interval];
    NSDateFormatter *_formatter=[[NSDateFormatter alloc]init];
    [_formatter setDateFormat:@"dd/MM/yy"];
    return [_formatter stringFromDate:date];
}

Trouble is, it keeps returning dates in 1972! (31/7/72) This is wrong, since it's a September 2011 date...

Can anyone suggest any solution?

Many thanks in advance,

Answer 1

Isn't epoch seconds since 1/1/1970? are you sure that you didn't leave the millisecond line in?

When I ran you're logic (without your line append 000 for ms), it worked. Here's what I did:

    NSString * timeStampString = @"1316641549";
    NSTimeInterval _interval=[timeStampString doubleValue];
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:_interval];
    NSLog(@"%@", date);

It outputted:

2011-09-21 17:46:14.384 Craplet[13218:707] 2011-09-21 21:45:49 +0000

Answer 2

Just divide your [timeStampString doubleValue] by a thousand like:

NSDate *date = [NSDate dateWithTimeIntervalSince1970:[timeStampString doubleValue]/1000.0];
NSDateFormatter *_formatter=[[NSDateFormatter alloc]init];
[_formatter setDateFormat:@"dd/MM/yy"];
return [_formatter stringFromDate:date];

or try [timeStampString longLongValue]/1000.0 instead

Good Luck!