Cómo convertir NSDate en formato relativo como "Hoy","Ayer","hace una semana","hace un mes","hace un año"?

Actualización rápida, gracias a la respuesta de objective-c de David Rönnqvist, funcionará para las fechas pasadas.

func relativeDateStringForDate(date : NSDate) -> NSString {

        let todayDate = NSDate()
        let units: NSCalendarUnit = [.Hour, .Day, .Month, .Year, .WeekOfYear]
        let components = NSCalendar.currentCalendar().components(units, fromDate: date , toDate: todayDate, options: NSCalendarOptions.MatchFirst )

        let year =  components.year
        let month = components.month
        let day = components.day
        let hour = components.hour
        let weeks = components.weekOfYear
        // if `date` is before "now" (i.e. in the past) then the components will be positive

        if components.year > 0 {
            return NSString.init(format: "%d years ago", year);
        } else if components.month > 0 {
            return NSString.init(format: "%d months ago", month);
        } else if components.weekOfYear > 0 {
            return NSString.init(format: "%d weeks ago", weeks);
        } else if (components.day > 0) {
            if components.day > 1 {
                return NSString.init(format: "%d days ago", day);
            } else {
                return "Yesterday";
            }
        } else {
            return NSString.init(format: "%d hours ago", hour);
        }
    }

DONDE DICE: SWIFT 3

Aquí hay una versión de Swift 3, para fechas pasadas, que maneja todas las unidades y singular o plural en la cadena devuelta.

Ejemplo De Uso:

let oneWeekAgo = Calendar.current.date(byAdding: .weekOfYear, value: -1, to: Date())!

print(relativePast(for: oneWeekAgo)) // output: "1 week ago"

Lo basé en un riff de Saurabh Yadav. Gracias.

func relativePast(for date : Date) -> String {

    let units = Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second, .weekOfYear])
    let components = Calendar.current.dateComponents(units, from: date, to: Date())

    if components.year! > 0 {
        return "\(components.year!) " + (components.year! > 1 ? "years ago" : "year ago")

    } else if components.month! > 0 {
        return "\(components.month!) " + (components.month! > 1 ? "months ago" : "month ago")

    } else if components.weekOfYear! > 0 {
        return "\(components.weekOfYear!) " + (components.weekOfYear! > 1 ? "weeks ago" : "week ago")

    } else if (components.day! > 0) {
        return (components.day! > 1 ? "\(components.day!) days ago" : "Yesterday")

    } else if components.hour! > 0 {
        return "\(components.hour!) " + (components.hour! > 1 ? "hours ago" : "hour ago")

    } else if components.minute! > 0 {
        return "\(components.minute!) " + (components.minute! > 1 ? "minutes ago" : "minute ago")

    } else {
        return "\(components.second!) " + (components.second! > 1 ? "seconds ago" : "second ago")
    }
}

Para evitar el problema de 24 horas mencionado por Budidino a la respuesta de David, lo alteré para que me guste esto a continuación -

- (NSString *)relativeDateStringForDate:(NSDate *)date
{

NSCalendarUnit units = NSDayCalendarUnit | NSWeekOfYearCalendarUnit |
NSMonthCalendarUnit | NSYearCalendarUnit ;
NSCalendar *cal = [NSCalendar currentCalendar];
NSDateComponents *components1 = [cal components:(NSCalendarUnitEra|NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay) fromDate:[NSDate date]];
NSDate *today = [cal dateFromComponents:components1];

components1 = [cal components:(NSCalendarUnitEra|NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay) fromDate:date];
NSDate *thatdate = [cal dateFromComponents:components1];

// if `date` is before "now" (i.e. in the past) then the components will be positive
NSDateComponents *components = [[NSCalendar currentCalendar] components:units
                                                               fromDate:thatdate
                                                                 toDate:today
                                                                options:0];

if (components.year > 0) {
    return [NSString stringWithFormat:@"%ld years ago", (long)components.year];
} else if (components.month > 0) {
    return [NSString stringWithFormat:@"%ld months ago", (long)components.month];
} else if (components.weekOfYear > 0) {
    return [NSString stringWithFormat:@"%ld weeks ago", (long)components.weekOfYear];
} else if (components.day > 0) {
    if (components.day > 1) {
        return [NSString stringWithFormat:@"%ld days ago", (long)components.day];
    } else {
        return @"Yesterday";
    }
} else {
    return @"Today";
}
}

Básicamente, crea 2 nuevas fechas sin piezas de tiempo incluidas.Entonces la comparación se hace para la diferencia de "días".

Aquí está mi respuesta (en Swift 3!) y por qué es mejor.

Respuesta:

func datePhraseRelativeToToday(from date: Date) -> String {

    // Don't use the current date/time. Use the end of the current day 
    // (technically 0h00 the next day). Apple's calculation of 
    // doesRelativeDateFormatting niavely depends on this start date.
    guard let todayEnd = dateEndOfToday() else {
        return ""
    }

    let calendar = Calendar.autoupdatingCurrent

    let units = Set([Calendar.Component.year,
                 Calendar.Component.month,
                 Calendar.Component.weekOfMonth,
                 Calendar.Component.day])

    let difference = calendar.dateComponents(units, from: date, to: todayEnd)

    guard let year = difference.year,
        let month = difference.month,
        let week = difference.weekOfMonth,
        let day = difference.day else {
            return ""
    }

    let timeAgo = NSLocalizedString("%@ ago", comment: "x days ago")

    let dateFormatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.locale = Locale.autoupdatingCurrent
        formatter.dateStyle = .medium
        formatter.doesRelativeDateFormatting = true
        return formatter
    }()

    if year > 0 {
        // sample output: "Jan 23, 2014"
        return dateFormatter.string(from: date)
    } else if month > 0 {
        let formatter = DateComponentsFormatter()
        formatter.unitsStyle = .brief // sample output: "1mth"
        formatter.allowedUnits = .month
        guard let timePhrase = formatter.string(from: difference) else {
            return ""
        }
        return String(format: timeAgo, timePhrase)
    } else if week > 0 {
        let formatter = DateComponentsFormatter()
        formatter.unitsStyle = .brief; // sample output: "2wks"
        formatter.allowedUnits = .weekOfMonth
        guard let timePhrase = formatter.string(from: difference) else {
            return ""
        }
        return String(format: timeAgo, timePhrase)
    } else if day > 1 {
            let formatter = DateComponentsFormatter()
            formatter.unitsStyle = .abbreviated; // sample output: "3d"
            formatter.allowedUnits = .day
            guard let timePhrase = formatter.string(from: difference) else {
                return ""
            }
            return String(format: timeAgo, timePhrase)
    } else {
        // sample output: "Yesterday" or "Today"
        return dateFormatter.string(from: date)
    }
}

func dateEndOfToday() -> Date? {
    let calendar = Calendar.autoupdatingCurrent
    let now = Date()
    let todayStart = calendar.startOfDay(for: now)
    var components = DateComponents()
    components.day = 1
    let todayEnd = calendar.date(byAdding: components, to: todayStart)
    return todayEnd
}

Recuerde: reutilice sus formateadores para evitar cualquier golpe de rendimiento! Sugerencia: las extensiones en DateFormatter y DateComponentsFormatter son buenas ideas.

Por qué es mejor:

• Utiliza "Yesterday" y "Today"de DateFormatter. Esto ya está traducido por Apple, lo que le ahorra trabajo!
• Utiliza DateComponentsFormatter ya traducido "1 semana" cadena. (De nuevo menos trabajo para ti, cortesía de Apple.) Todo lo que tienes que hacer es traducir la cadena "%@ ago".
• Las otras respuestas calculan incorrectamente la hora en que el día cambia de "hoy" a "ayer" a etc. Las constantes fijas son un gran NO-NO porque razones. Además, las otras respuestas usan la fecha/hora actual cuando deberían usar el final de la fecha/hora del día actual.
• Utiliza autoupdatingCurrent para Calendar & Locale, lo que garantiza que su aplicación sea inmediatamente actualizado con el calendario del usuario y las preferencias de idioma en la configuración.app

Esta respuesta fue inspirada por DateTools en GitHub.

Compruebe NSDate-TimeAgo, también es compatible con varios idiomas.

Tendrá que resolver esta lógica usted mismo. Tendrá que determinar el número de días entre esas dos fechas.

Aquí hay un enfoque relativamente ingenuo:

+ (NSString *) dateDifference:(NSDate *)date
{
    const NSTimeInterval secondsPerDay = 60 * 60 * 24;
    NSTimeInterval diff = [date timeIntervalSinceNow] * -1.0;

    // if the difference is negative, then the given date/time is in the future
    // (because we multiplied by -1.0 to make it easier to follow later)
    if (diff < 0)
        return @"In the future";

    diff /= secondsPerDay; // get the number of days

    // if the difference is less than 1, the date occurred today, etc.
    if (diff < 1)
        return @"Today";
    else if (diff < 2)
        return @"Yesterday";
    else if (diff < 8)
        return @"Last week";
    else
        return [date description]; // use a date formatter if necessary
}

Es ingenuo por varias razones:

1. No tiene en cuenta los días bisiestos
2. Se asume que hay 86400 segundos en un día (hay tal cosa como segundos intercalares!)

Sin embargo, esto debería al menos ayudarte a dirigirte en la dirección correcta. Además, evite usar get en nombres de métodos. El uso de get en un nombre de método normalmente indica que el llamador debe proporcionar su propio búfer de salida. Consideremos el método de NSArray, getItems:range:, y el método de NSString, getCharacters:range:.

NSString* AgoStringFromTime(NSDate* dateTime)
{
    NSDictionary *timeScale = @{@"sec"  :@1,
                                @"min"  :@60,
                                @"hr"   :@3600,
                                @"day"  :@86400,
                                @"week" :@605800,
                                @"month":@2629743,
                                @"year" :@31556926};
    NSString *scale;
    int timeAgo = 0-(int)[dateTime timeIntervalSinceNow];
    if (timeAgo < 60) {
        scale = @"sec";
    } else if (timeAgo < 3600) {
        scale = @"min";
    } else if (timeAgo < 86400) {
        scale = @"hr";
    } else if (timeAgo < 605800) {
        scale = @"day";
    } else if (timeAgo < 2629743) {
        scale = @"week";
    } else if (timeAgo < 31556926) {
        scale = @"month";
    } else {
        scale = @"year";
    }

    timeAgo = timeAgo/[[timeScale objectForKey:scale] integerValue];
    NSString *s = @"";
    if (timeAgo > 1) {
        s = @"s";
    }

    return [NSString stringWithFormat:@"%d %@%@", timeAgo, scale, s];
}

Aquí está el código que creé para mi uso:

+ (NSString*) getTimestampForDate:(NSDate*)date {

    NSDate* sourceDate = date;

    // Timezone Offset compensation (optional, if your target users are limited to a single time zone.)

    NSTimeZone* sourceTimeZone = [NSTimeZone timeZoneWithName:@"America/New_York"];
    NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone];

    NSInteger sourceGMTOffset = [sourceTimeZone secondsFromGMTForDate:sourceDate];
    NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:sourceDate];

    NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset;

    NSDate* destinationDate = [[NSDate alloc] initWithTimeInterval:interval sinceDate:sourceDate];

    // Timestamp calculation (based on compensation)

    NSCalendar* currentCalendar = [NSCalendar currentCalendar];
    NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit;

    NSDateComponents *differenceComponents = [currentCalendar components:unitFlags fromDate:destinationDate toDate:[NSDate date] options:0];//Use `date` instead of `destinationDate` if you are not using Timezone offset correction

    NSInteger yearDifference = [differenceComponents year];
    NSInteger monthDifference = [differenceComponents month];
    NSInteger dayDifference = [differenceComponents day];
    NSInteger hourDifference = [differenceComponents hour];
    NSInteger minuteDifference = [differenceComponents minute];

    NSString* timestamp;

    if (yearDifference == 0
        && monthDifference == 0
        && dayDifference == 0
        && hourDifference == 0
        && minuteDifference <= 2) {

        //"Just Now"

        timestamp = @"Just Now";

    } else if (yearDifference == 0
               && monthDifference == 0
               && dayDifference == 0
               && hourDifference == 0
               && minuteDifference < 60) {

        //"13 minutes ago"

        timestamp = [NSString stringWithFormat:@"%ld minutes ago", (long)minuteDifference];

    } else if (yearDifference == 0
               && monthDifference == 0
               && dayDifference == 0
               && hourDifference == 1) {

        //"1 hour ago" EXACT

        timestamp = @"1 hour ago";

    } else if (yearDifference == 0
               && monthDifference == 0
               && dayDifference == 0
               && hourDifference < 24) {

        timestamp = [NSString stringWithFormat:@"%ld hours ago", (long)hourDifference];

    } else {

        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setLocale:[NSLocale currentLocale]];

        NSString* strDate, *strDate2 = @"";

        if (yearDifference == 0
            && monthDifference == 0
            && dayDifference == 1) {

            //"Yesterday at 10:23 AM", "Yesterday at 5:08 PM"

            [formatter setDateFormat:@"hh:mm a"];
            strDate = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"Yesterday at %@", strDate];

        } else if (yearDifference == 0
                   && monthDifference == 0
                   && dayDifference < 7) {

            //"Tuesday at 7:13 PM"

            [formatter setDateFormat:@"EEEE"];
            strDate = [formatter stringFromDate:date];
            [formatter setDateFormat:@"hh:mm a"];
            strDate2 = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"%@ at %@", strDate, strDate2];

        } else if (yearDifference == 0) {

            //"July 4 at 7:36 AM"

            [formatter setDateFormat:@"MMMM d"];
            strDate = [formatter stringFromDate:date];
            [formatter setDateFormat:@"hh:mm a"];
            strDate2 = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"%@ at %@", strDate, strDate2];

        } else {

            //"March 24 2010 at 4:50 AM"

            [formatter setDateFormat:@"d MMMM yyyy"];
            strDate = [formatter stringFromDate:date];
            [formatter setDateFormat:@"hh:mm a"];
            strDate2 = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"%@ at %@", strDate, strDate2];
        }
    }

    return timestamp;
}

Esto es solo una copia de una respuesta anterior pero devuelve Just now si es menos de cinco segundos.

func relativePast(for date : Date) -> String {

    let units = Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second, .weekOfYear])
    let components = Calendar.current.dateComponents(units, from: date, to: Date())

    if components.year! > 0 {
        return "\(components.year!) " + (components.year! > 1 ? "years ago" : "year ago")

    } else if components.month! > 0 {
        return "\(components.month!) " + (components.month! > 1 ? "months ago" : "month ago")

    } else if components.weekOfYear! > 0 {
        return "\(components.weekOfYear!) " + (components.weekOfYear! > 1 ? "weeks ago" : "week ago")

    } else if (components.day! > 0) {
        return (components.day! > 1 ? "\(components.day!) days ago" : "Yesterday")

    } else if components.hour! > 0 {
        return "\(components.hour!) " + (components.hour! > 1 ? "hours ago" : "hour ago")

    } else if components.minute! > 0 {
        return "\(components.minute!) " + (components.minute! > 1 ? "minutes ago" : "minute ago")

    } else {
        return "\(components.second!) " + (components.second! > 5 ? "seconds ago" : "Just Now".replacingOccurrences(of: "0", with: "")
    }
}

El problema con doesRelativeDateFormatting es que está bastante limitado a Yesterday, Today, Tomorrow. Si estás buscando algo más completo, entonces echa un vistazo a las respuestas aquí.

Complate Code If Futures Dates

NSCalendarUnit units = NSCalendarUnitDay | NSCalendarUnitWeekOfYear | 
                           NSCalendarUnitMonth | NSCalendarUnitYear;


    NSDateComponents *components = [[NSCalendar currentCalendar] components:units fromDate:date toDate:[NSDate date] options:0];

    if (components.year < 0) {
            return [NSString stringWithFormat:@"%ld years from now", labs((long)components.year)];
        } else if (components.month < 0) {
            return [NSString stringWithFormat:@"%ld months from now", labs((long)components.month)];
        } else if (components.weekOfYear < 0) {
            return [NSString stringWithFormat:@"%ld weeks from now", labs((long)components.weekOfYear)];
        } else if (components.day < 0) {
            if (components.day < 1) {
                return [NSString stringWithFormat:@"%ld days from now", labs((long)components.day)];
            } else {
                return @"Tomorrow";
            }
        }
        else if (components.year > 0) {
            return [NSString stringWithFormat:@"%ld years ago", (long)components.year];
        } else if (components.month > 0) {
            return [NSString stringWithFormat:@"%ld months ago", (long)components.month];
        } else if (components.weekOfYear > 0) {
            return [NSString stringWithFormat:@"%ld weeks ago", (long)components.weekOfYear];
        } else if (components.day > 0) {
            if (components.day > 1) {
                return [NSString stringWithFormat:@"%ld days ago", (long)components.day];
            } else {
                return @"Yesterday";
            }
        } else {
            return @"Today";
        }

He adjuntado demo aquí por favor encontrar en este enlace. TimestampAgo-Demo

Gracias a n00bprogrammer

Edit: - Hice cambios en Sourcetimezone con [NSTimeZone systemTimeZone] porque debido a la zona horaria estática , el problema ocurrió en formato GMT o UTC. (segundo va en menos) y cambiar los métodos obsoletos.

Aquí está mi solución en Swift 2 que evitan el problema de 24 horas comparando dos fechas con un tiempo cero.

extension NSDate {

private func dateWithZeroTime(date: NSDate) -> NSDate? {
    let calendar = NSCalendar.currentCalendar()
    let units: NSCalendarUnit = [.Day, .WeekOfYear, .Month, .Year]
    let components = calendar.components(units, fromDate: date)
    return calendar.dateFromComponents(components)
}

private func thisDay() -> NSDate? {
    return self.dateWithZeroTime(self)
}

private func today() -> NSDate? {
    return self.dateWithZeroTime(NSDate())
}

var relativeFormat: String? {
    let today = self.today()
    let thisDay = self.thisDay()

    let formatter = NSDateFormatter()
    formatter.dateStyle = NSDateFormatterStyle.LongStyle
    let dateString = formatter.stringFromDate(self)

    if nil != thisDay && nil != today {
        let units: NSCalendarUnit = [.Day, .WeekOfYear, .Month, .Year]
        let components = NSCalendar.currentCalendar().components(units, fromDate: thisDay!, toDate: today!, options: [])

        if (components.year > 0) {
            return components.year == 1 ? "A year ago, \(dateString)" : "\(components.year) years ago, \(dateString)"
        } else if (components.month > 0) {
            return components.month == 1 ? "A month ago, \(dateString)" : "\(components.month) months ago, \(dateString)"
        } else if (components.weekOfYear > 0) {
            return components.weekOfYear == 1 ? "A week ago, \(dateString)" : "\(components.weekOfYear) weeks ago, \(dateString)"
        } else if (components.day > 0) {
            return components.day == 1 ? "Yesterday, \(dateString)" : "\(self.dayOfTheWeek()), \(dateString)"
        } else {
            return "Today"
        }
    }

    return nil
}

func dayOfTheWeek() -> String {
    let weekdays = [
        "Sunday",
        "Monday",
        "Tuesday",
        "Wednesday",
        "Thursday",
        "Friday",
        "Saturday"
    ]

    let calendar: NSCalendar = NSCalendar.currentCalendar()
    let components: NSDateComponents = calendar.components(.Weekday, fromDate: self)
    return weekdays[components.weekday - 1]
}
}

let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full

let now = NSDate()


let dateMakerFormatter = DateFormatter()

dateMakerFormatter.dateFormat = "yyyy/MM/dd HH:mm:ss z"
let dateString = "2017-03-13 10:38:54 +0000"
let stPatricksDay = dateMakerFormatter.date(from: dateString)!


let calendar = NSCalendar.current



let components = calendar.dateComponents([.hour, .minute,.weekOfMonth,.day,.year,.month,.second], from: stPatricksDay, to: now as Date)



if components.year! > 0 {
    formatter.allowedUnits = .year
} else if components.month! > 0 {
    formatter.allowedUnits = .month
} else if components.weekOfMonth! > 0 {
    formatter.allowedUnits = .weekOfMonth
} else if components.day! > 0 {
    formatter.allowedUnits = .day
} else if components.hour! > 0 {
    formatter.allowedUnits = .hour
} else if components.minute! > 0 {
    formatter.allowedUnits = .minute
} else {
    formatter.allowedUnits = .second
}

let formatString = NSLocalizedString("%@ ago", comment: "Used to say how much time has passed. e.g. '2 hours ago'")

 let timeString = formatter.string(from: components)

String(format: formatString, timeString!)

Formatear el "sourceDate" dado como "5:56 pm" para hoy, "ayer" para cualquier momento ayer, "16 de enero" para cualquier día del mismo año y "16 de enero de 2014". Estoy publicando mi propio método.

sourceDate = //some date that you need to take into consideration


 NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitMinute | NSCalendarUnitHour | NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
    NSDateComponents *sourceDateComponents = [[NSCalendar currentCalendar] components:NSCalendarUnitMinute | NSCalendarUnitHour | NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate: sourceDate];

    NSString* timestamp;

    NSDateFormatter *formatSourceDate   =   [NSDateFormatter new];
    [formatSourceDate setAMSymbol:@"AM"];
    [formatSourceDate setPMSymbol:@"PM"];

    //same day - time in h:mm am/pm
    if (components.day == sourceDateComponents.day) {
        NSLogInfo(@"time");
        [formatSourceDate setDateFormat:@"h:mm a"];
        timestamp = [NSString stringWithFormat:@"%@",[formatSourceDate stringFromDate:date]];
        return timestamp;
    }
    else if (components.day - sourceDateComponents.day == 1) {
        //yesterday
        timestamp = NSLocalizedString(@"Yesterday", nil);
        return timestamp;
    }
    if (components.year == sourceDateComponents.year) {
        //september 29, 5:56 pm
        [formatSourceDate setDateFormat:@"MMMM d"];
        timestamp = [NSString stringWithFormat:@"%@",[formatSourceDate stringFromDate:date]];
        return timestamp;
    }
    [formatSourceDate setDateFormat:@"MMMM d year"];
    timestamp = [NSString stringWithFormat:@"%@",[formatSourceDate stringFromDate:date]];
    return timestamp;

    NSLogInfo(@"Timestamp : %@",timestamp);