143

如何NSDate在 Objective C 或/和 Swift 中将 UTC 转换为本地时区 NSDate？

4

15 回答 15

141 
NSTimeInterval seconds; // assume this exists
NSDate* ts_utc = [NSDate dateWithTimeIntervalSince1970:seconds];

NSDateFormatter* df_utc = [[[NSDateFormatter alloc] init] autorelease];
[df_utc setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]];
[df_utc setDateFormat:@"yyyy.MM.dd G 'at' HH:mm:ss zzz"];

NSDateFormatter* df_local = [[[NSDateFormatter alloc] init] autorelease];
[df_local setTimeZone:[NSTimeZone timeZoneWithName:@"EST"]];
[df_local setDateFormat:@"yyyy.MM.dd G 'at' HH:mm:ss zzz"];

NSString* ts_utc_string = [df_utc stringFromDate:ts_utc];
NSString* ts_local_string = [df_local stringFromDate:ts_utc];

// you can also use NSDateFormatter dateFromString to go the opposite way

格式化字符串参数表：

https://waracle.com/iphone-nsdateformatter-date-formatting-table/

如果性能是重中之重，您可能需要考虑使用strftime

https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/strftime.3.html

于 2011-08-31T15:37:40.453 回答
107

编辑当我写这篇文章时，我不知道我应该使用可能是更好的方法的 dateformatter，所以slf也请查看 的答案。

我有一个以 UTC 格式返回日期的网络服务。我toLocalTime用来将其转换为当地时间并toGlobalTime在需要时转换回来。

这就是我得到答案的地方：

https://agilewarrior.wordpress.com/2012/06/27/how-to-convert-nsdate-to-different-time-zones/ 

@implementation NSDate(Utils)

-(NSDate *) toLocalTime
{
  NSTimeZone *tz = [NSTimeZone defaultTimeZone];
  NSInteger seconds = [tz secondsFromGMTForDate: self];
  return [NSDate dateWithTimeInterval: seconds sinceDate: self];
}

-(NSDate *) toGlobalTime
{
  NSTimeZone *tz = [NSTimeZone defaultTimeZone];
  NSInteger seconds = -[tz secondsFromGMTForDate: self];
  return [NSDate dateWithTimeInterval: seconds sinceDate: self];
}

@end
于 2011-10-12T11:49:14.753 回答
49

我发现的最简单的方法是：

NSDate *someDateInUTC = …;
NSTimeInterval timeZoneSeconds = [[NSTimeZone localTimeZone] secondsFromGMT];
NSDate *dateInLocalTimezone = [someDateInUTC dateByAddingTimeInterval:timeZoneSeconds];
于 2014-05-30T18:11:02.020 回答
38

Swift 3+：UTC 到本地和本地到 UTC

extension Date {

    // Convert UTC (or GMT) to local time
    func toLocalTime() -> Date {
        let timezone = TimeZone.current
        let seconds = TimeInterval(timezone.secondsFromGMT(for: self))
        return Date(timeInterval: seconds, since: self)
    }

    // Convert local time to UTC (or GMT)
    func toGlobalTime() -> Date {
        let timezone = TimeZone.current
        let seconds = -TimeInterval(timezone.secondsFromGMT(for: self))
        return Date(timeInterval: seconds, since: self)
    }
}
于 2017-05-15T11:01:56.153 回答
26

如果您想要本地日期和时间。试试这个代码： -

NSString *localDate = [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterMediumStyle timeStyle:NSDateFormatterMediumStyle];
于 2013-05-20T06:11:35.720 回答
7

将您的 UTC 日期转换为本地日期

-(NSString *)getLocalDateTimeFromUTC:(NSString *)strDate
{
    NSDateFormatter *dtFormat = [[NSDateFormatter alloc] init];
    [dtFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    [dtFormat setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
    NSDate *aDate = [dtFormat dateFromString:strDate];

    [dtFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    [dtFormat setTimeZone:[NSTimeZone systemTimeZone]];

    return [dtFormat stringFromDate:aDate];
}

像这样使用

NSString *localDate = [self getLocalDateTimeFromUTC:@"yourUTCDate"];
于 2016-03-08T08:53:43.560 回答
6

这里的输入是一个字符串 currentUTCTime（格式为 08/30/2012 11:11）将 GMT 的输入时间转换为系统设置的区域时间

//UTC time
NSDateFormatter *utcDateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[utcDateFormatter setDateFormat:@"MM/dd/yyyy HH:mm"];
[utcDateFormatter setTimeZone :[NSTimeZone timeZoneForSecondsFromGMT: 0]];

// utc format
NSDate *dateInUTC = [utcDateFormatter dateFromString: currentUTCTime];

// offset second
NSInteger seconds = [[NSTimeZone systemTimeZone] secondsFromGMT];

// format it and send
NSDateFormatter *localDateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[localDateFormatter setDateFormat:@"MM/dd/yyyy HH:mm"];
[localDateFormatter setTimeZone :[NSTimeZone timeZoneForSecondsFromGMT: seconds]];

// formatted string
NSString *localDate = [localDateFormatter stringFromDate: dateInUTC];
return localDate;
于 2012-08-31T09:15:33.333 回答
4 
//This is basic way to get time of any GMT time.

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"hh:mm a"];  // 09:30 AM
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:1]]; // For GMT+1
NSString *time = [formatter stringFromDate:[NSDate date]];  // Current time
于 2014-11-21T06:58:57.307 回答
3

将日期从 UTC 日历转换为具有适当本地NSTimeZone的日期。

于 2009-08-12T20:28:14.283 回答
2

我编写此方法将日期时间转换为我们的 LocalTimeZone

- 这里 (NSString *)TimeZone 参数是一个服务器时区

-(NSString *)convertTimeIntoLocal:(NSString *)defaultTime :(NSString *)TimeZone
{
    NSDateFormatter *serverFormatter = [[NSDateFormatter alloc] init];
    [serverFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:TimeZone]];
    [serverFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *theDate = [serverFormatter dateFromString:defaultTime];
    NSDateFormatter *userFormatter = [[NSDateFormatter alloc] init];
    [userFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    [userFormatter setTimeZone:[NSTimeZone localTimeZone]];
    NSString *dateConverted = [userFormatter stringFromDate:theDate];
    return dateConverted;
}
于 2016-01-09T09:37:47.480 回答
1

由于似乎没有人在使用NSDateComponents，所以我想我会投一个... 在这个版本中，没有NSDateFormatter使用，因此没有字符串解析，并且NSDate不用于表示 GMT (UTC) 之外的时间。原件NSDate在变量中i_date。

NSCalendar *anotherCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:i_anotherCalendar];
anotherCalendar.timeZone = [NSTimeZone timeZoneWithName:i_anotherTimeZone];

NSDateComponents *anotherComponents = [anotherCalendar components:(NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond | NSCalendarUnitNanosecond) fromDate:i_date];

// The following is just for checking   
anotherComponents.calendar = anotherCalendar; // anotherComponents.date is nil without this
NSDate *anotherDate = anotherComponents.date;

i_anotherCalendar可以是NSCalendarIdentifierGregorian或任何其他日历。NSStringallowed for可以通过i_anotherTimeZone获得[NSTimeZone knownTimeZoneNames]，但anotherCalendar.timeZone可以是[NSTimeZone defaultTimeZone]或[NSTimeZone localTimeZone]全部[NSTimeZone systemTimeZone]。

它实际上是anotherComponents在新时区保持时间。您会注意到anotherDate等于i_date，因为它的时间为 GMT (UTC)。

于 2014-12-21T14:01:32.297 回答
0

请使用此代码。

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"]; 
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
NSDate *date = [dateFormatter dateFromString:@"2015-04-01T11:42:00"]; // create date from string

[dateFormatter setDateFormat:@"EEE, MMM d, yyyy - h:mm a"];
[dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
NSString *timestamp = [dateFormatter stringFromDate:date];
于 2021-01-14T08:48:49.837 回答
0

Solution for SwiftDate library:

// Take date by seconds in UTC time zone
var viewModelDate: Date = DateInRegion(seconds: Double(backendModel.scheduledTimestamp)).date 

...

// Convert date to local timezone and convert to string by format rule.
label.text = viewModelDate.convertTo(region: .current).toFormat(" EEE MM/dd j:mm")
于 2021-06-09T04:27:53.900 回答
0

你可以试试这个：

NSDate *currentDate = [[NSDate alloc] init];
NSTimeZone *timeZone = [NSTimeZone defaultTimeZone];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateStyle:NSDateFormatterLongStyle];
[dateFormatter setTimeStyle:NSDateFormatterLongStyle];
[dateFormatter setTimeZone:timeZone];
[dateFormatter setDateFormat:@"ZZZ"];
NSString *localDateString = [dateFormatter stringFromDate:currentDate];
NSMutableString *mu = [NSMutableString stringWithString:localDateString];
[mu insertString:@":" atIndex:3];
 NSString *strTimeZone = [NSString stringWithFormat:@"(GMT%@)%@",mu,timeZone.name];
 NSLog(@"%@",strTimeZone);
于 2018-01-09T11:10:03.573 回答
-2

将 UTC 时间转换为当前时区。

调用函数

NSLocale *locale = [NSLocale autoupdatingCurrentLocale];

NSString *myLanguageCode = [locale objectForKey: NSLocaleLanguageCode];
NSString *myCountryCode = [locale objectForKey: NSLocaleCountryCode];

NSString *rfc3339DateTimeString = @"2015-02-15 00:00:00"];
NSDate *myDateTime = (NSDate*)[_myCommonFunctions _ConvertUTCTimeToLocalTimeWithFormat:rfc3339DateTimeString LanguageCode:myLanguageCode CountryCode:myCountryCode Formated:NO];

功能

-NSObject*)_ConvertUTCTimeToLocalTimeWithFormat:rfc3339DateTimeString     LanguageCode:(NSString *)lgc CountryCode:(NSString *)ctc Formated:(BOOL) formated
{
    NSDateFormatter *sUserVisibleDateFormatter = nil;
    NSDateFormatter *sRFC3339DateFormatter = nil;

    NSTimeZone *timeZone = [NSTimeZone defaultTimeZone];

    if (sRFC3339DateFormatter == nil)
    {
        sRFC3339DateFormatter = [[NSDateFormatter alloc] init];

        NSLocale *myPOSIXLocale = [[NSLocale alloc] initWithLocaleIdentifier:[NSString stringWithFormat:@"%@", timeZone]];

        [sRFC3339DateFormatter setLocale:myPOSIXLocale];
        [sRFC3339DateFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss'Z'"];
        [sRFC3339DateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
    }

    // Convert the RFC 3339 date time string to an NSDate.
    NSDate *date = [sRFC3339DateFormatter dateFromString:rfc3339DateTimeString];

    if (formated == YES)
    {
        NSString *userVisibleDateTimeString;

        if (date != nil)
        {
            if (sUserVisibleDateFormatter == nil)
            {
                sUserVisibleDateFormatter = [[NSDateFormatter alloc] init];
                [sUserVisibleDateFormatter setDateStyle:NSDateFormatterMediumStyle];
                [sUserVisibleDateFormatter setTimeStyle:NSDateFormatterShortStyle];
            }

            // Convert the date object to a user-visible date string.
            userVisibleDateTimeString = [sUserVisibleDateFormatter stringFromDate:date];

            return (NSObject*)userVisibleDateTimeString;
        }
    }

    return (NSObject*)date;
}
于 2015-02-15T17:30:37.450 回答