[英]iOS: Convert UTC NSDate to local Timezone
如何在 Objective C 或/和 Swift 中將 UTC NSDate
轉換為本地時區 NSDate?
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
格式化字符串參數表:
https://waracle.com/iphone-nsdateformatter-date-formatting-table/
如果優先考慮性能,您可能需要考慮使用strftime
編輯當我寫這篇文章時,我不知道我應該使用 dateformatter 這可能是一種更好的方法,所以也請查看slf
的答案。
我有一個以 UTC 返回日期的網絡服務。 我用toLocalTime
將其轉換為本地時間和toGlobalTime
到如果需要轉換回。
這是我從這里得到答案的地方:
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
我發現的最簡單的方法是這樣的:
NSDate *someDateInUTC = …;
NSTimeInterval timeZoneSeconds = [[NSTimeZone localTimeZone] secondsFromGMT];
NSDate *dateInLocalTimezone = [someDateInUTC dateByAddingTimeInterval:timeZoneSeconds];
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)
}
}
如果您想要本地日期和時間。 試試這個代碼:-
NSString *localDate = [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterMediumStyle timeStyle:NSDateFormatterMediumStyle];
將您的 UTC 日期轉換為本地日期
-(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];
}
像這樣使用
NSString *localDate = [self getLocalDateTimeFromUTC:@"yourUTCDate"];
這里輸入的是一個字符串 currentUTCTime(格式為 08/30/2012 11:11)將輸入的 GMT 時間轉換為系統設置的時區時間
//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;
//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
將日期從 UTC 日歷轉換為具有適當本地NSTimeZone 的日期。
我編寫此方法將日期時間轉換為我們的 LocalTimeZone
- 這里 (NSString *)TimeZone 參數是服務器時區
-(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;
}
由於似乎沒有人使用NSDateComponents
,我想我會NSDateComponents
一分... 在這個版本中,沒有使用NSDateFormatter
,因此沒有字符串解析,並且NSDate
不用於表示 GMT (UTC) 之外的時間。 原始NSDate
位於變量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
或任何其他日歷。 i_anotherTimeZone
允許的NSString
可以通過[NSTimeZone knownTimeZoneNames]
獲取,但anotherCalendar.timeZone
可以是[NSTimeZone defaultTimeZone]
或[NSTimeZone localTimeZone]
或[NSTimeZone systemTimeZone]
。
它實際上是在新時區中保存時間的anotherComponents
。 您會注意到anotherDate
等於i_date
,因為它以格林威治標准時間 (UTC) 保存時間。
你可以試試這個:
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);
請使用此代碼。
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];
SwiftDate庫的解決方案:
// 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")
將 UTC 時間轉換為當前時區。
調用函數
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;
}
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