ios - NSDateFormatter dateFromString returns date with wrong month

Question

I have the following code:

for (i=0; i<json.count; i++) {

    NSDictionary *bodyDictionary = [json objectAtIndex:i];
    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
    [formatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];
    [formatter setLocale:[NSLocale currentLocale]];
    [formatter setDateFormat:@"yyyy-mm-dd HH:mm:ss"];
    NSDate *date = [formatter dateFromString:[bodyDictionary objectForKey:@"date"]];
    NSNumber* thisVolume = [NSNumber numberWithInteger:[[bodyDictionary objectForKey:@"volume"] integerValue]];

    NSTimeInterval timeNumber = [date timeIntervalSince1970];

    CGPoint point = CGPointMake(timeNumber, thisVolume.doubleValue);
    NSValue *pointValue = [NSValue valueWithCGPoint:point];
    [dataArray addObject:pointValue];

}

Where I cycle through an array of dictionary objects - one of which is a date. I have checked the format of the incoming date string - which is:

2020-07-15 07:01:00

However - once it has been through the dateformatter - the NSDate comes out as:

2020-01-15 07:01:00

Answer 1

Your problem is that you are using m for both months and minutes.

Instead of

[formatter setDateFormat:@"yyyy-mm-dd HH:mm:ss"];

you have to use:

[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

Click here to see the full list of symbols you can use.

For Swift

formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"