Question

I have the following NSString:

NSString * dateString = @"2012-01-24T14:59:01Z";

I want to create an NSDate from that string. I looked up the NSDate Class Reference and thought of using dateWithNaturalLanguageString::

Creates and returns an NSDate object set to the date and time
specified by a given string.

+ (id)dateWithNaturalLanguageString:(NSString *)string

Parameters
string
A string that contains a colloquial specification of a date,
such as “last Tuesday at dinner,” “3pm December 31, 2001,” “12/31/01,”
or “31/12/01.”
Return Value
A new NSDate object set to the current
date and time specified by string.

However, when I’m trying to use it like this:

NSDate * date = [NSDate dateWithNaturalLanguageString:dateString];

I’m getting the following error:

No known class method for selector ‘dateWithNaturalLanguageString:’

Answer 1

Found exactly what I was looking for here. It’s an RFC 3339 date-time.

- (NSString *)userVisibleDateTimeStringForRFC3339DateTimeString:(NSString *)rfc3339DateTimeString
    // Returns a user-visible date time string that corresponds to the
    // specified RFC 3339 date time string. Note that this does not handle
    // all possible RFC 3339 date time strings, just one of the most common
    // styles.
{
    NSString *          userVisibleDateTimeString;
    NSDateFormatter *   rfc3339DateFormatter;
    NSLocale *          enUSPOSIXLocale;
    NSDate *            date;
    NSDateFormatter *   userVisibleDateFormatter;

    userVisibleDateTimeString = nil;

    // Convert the RFC 3339 date time string to an NSDate.

    rfc3339DateFormatter = [[[NSDateFormatter alloc] init] autorelease];

    enUSPOSIXLocale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"] autorelease];

    [rfc3339DateFormatter setLocale:enUSPOSIXLocale];
    [rfc3339DateFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss'Z'"];
    [rfc3339DateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];

    date = [rfc3339DateFormatter dateFromString:rfc3339DateTimeString];
    if (date != nil) {

        // Convert the NSDate to a user-visible date string.

        userVisibleDateFormatter = [[[NSDateFormatter alloc] init] autorelease];
        assert(userVisibleDateFormatter != nil);

        [userVisibleDateFormatter setDateStyle:NSDateFormatterShortStyle];
        [userVisibleDateFormatter setTimeStyle:NSDateFormatterShortStyle];

        userVisibleDateTimeString = [userVisibleDateFormatter stringFromDate:date];
    }
    return userVisibleDateTimeString;
}