如何在Objective C或/和Swift中将UTC NSDate
转换为本地时区NSDate?
答案 0 :(得分:137)
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/
如果优先考虑性能,您可能需要考虑使用strftime
答案 1 :(得分:106)
编辑当我写这篇文章时,我不知道我应该使用dateformatter这可能是一种更好的方法,所以也请查看slf
的答案。
我有一个以UTC格式返回日期的网络服务。我使用toLocalTime
将其转换为本地时间,toGlobalTime
转换回来,如果需要。
这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
答案 2 :(得分:47)
我发现最简单的方法是:
NSDate *someDateInUTC = …;
NSTimeInterval timeZoneSeconds = [[NSTimeZone localTimeZone] secondsFromGMT];
NSDate *dateInLocalTimezone = [someDateInUTC dateByAddingTimeInterval:timeZoneSeconds];
答案 3 :(得分:27)
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)
}
}
答案 4 :(得分:25)
如果您想要当地的日期和时间。试试这个代码: -
NSString *localDate = [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterMediumStyle timeStyle:NSDateFormatterMediumStyle];
答案 5 :(得分:6)
此处输入为字符串currentUTCTime(格式为08/30/2012 11:11)将GMT中的输入时间转换为系统设置区时间
//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;
答案 6 :(得分:5)
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"];
答案 7 :(得分:3)
Convert the date到具有相应的本地NSTimeZone的<。}。
答案 8 :(得分:3)
//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
答案 9 :(得分:2)
我编写此方法将日期时间转换为LocalTimeZone
-Here(NSString *)TimeZone参数是服务器时区
-(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;
}
答案 10 :(得分:1)
由于似乎没有人使用NSDateComponents
,我以为我会推荐一个......
在此版本中,不使用NSDateFormatter
,因此不进行字符串解析,NSDate
不用于表示GMT(UTC)之外的时间。原始NSDate
位于变量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。
可以使用NSString
获取i_anotherTimeZone
允许的[NSTimeZone knownTimeZoneNames]
,但anotherCalendar.timeZone
可以是[NSTimeZone defaultTimeZone]
或[NSTimeZone localTimeZone]
或[NSTimeZone systemTimeZone]
。
实际上anotherComponents
将时间保留在新时区。您会注意到anotherDate
等于i_date
,因为它以GMT(UTC)保留时间。
答案 11 :(得分:0)
你可以尝试这个:
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);
答案 12 :(得分: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];
答案 13 :(得分:0)
SwiftDate 库的解决方案:
// 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")
答案 14 :(得分:-1)
将UTC时间转换为当前时区。
通话功能
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;
}