iOS 本地时间、UTC时间、时间戳等操作、获取当前年月日

//获得当前时间并且转为字符串

-(NSString*)dateTransformToTimeString
{
NSDate*currentDate=[NSDatedate];//获得当前时间为UTC时间2014-07-1607:54:36UTC(UTC时间比标准时间差8小时)
//转为字符串
NSDateFormatter*df=[[NSDateFormatteralloc]init];//实例化时间格式类
[dfsetDateFormat:@"yyyy-MM-ddHH:mm:ss"];//格式化
//2014-07-1607:54:36(NSString类)
NSString*timeString=[dfstringFromDate:currentDate];
returntimeString;
}

//获取当前时间转为时间戳

-(NSString*)dateTransformToTimeSp
{
UInt64recordTime=[[NSDatedate]timeIntervalSince1970]*1000;//客户端当前13位毫秒级时间戳
NSString*timeSp=[NSStringstringWithFormat:@"%llu",recordTime];//时间戳转字符串(13位毫秒级时间戳字符串)
returntimeSp;
}

1//时间戳字符串1469193006001（毫秒）1469193006.001（毫秒，1469193006001234（微秒）1469193006.001234（微秒）转UTC时间2016-08-11T07:00:55.611Z
2-(NSString*)timespToUTCFormat:(NSString*)timesp
3{
4NSString*timeString=[timespstringByReplacingOccurrencesOfString:@"."withString:@""];
5if(timeString.length>=10){
6NSString*second=[timeStringsubstringToIndex:10];
7NSString*milliscond=[timeStringsubstringFromIndex:10];
8NSString*timeStampString=[NSStringstringWithFormat:@"%@.%@",second,milliscond];
9NSTimeInterval_interval=[timeStampStringdoubleValue];
10NSDate*date=[NSDatedateWithTimeIntervalSince1970:_interval];
11
12NSDateFormatter*dateFormatter=[[NSDateFormatteralloc]init];
13NSTimeZone*timeZone=[NSTimeZonetimeZoneWithName:@"UTC"];
14[dateFormattersetTimeZone:timeZone];
15[dateFormattersetDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"];
16NSString*dateString=[dateFormatterstringFromDate:date];
17
18returndateString;
19}
20return@"";
21}

//13位时间戳1469193006001（毫秒）转系统时间2016-08-1108:55:36

1+(NSString*)timespToYMDFormat:(NSNumber*)timesp
2{
3NSString*stime=[timespstringValue];
4NSTimeIntervaltime=[[stimesubstringToIndex:10]doubleValue];
5NSDate*detaildate=[NSDatedateWithTimeIntervalSince1970:time];
6NSDateFormatter*dateFormatter=[[NSDateFormatteralloc]init];
7[dateFormattersetDateFormat:@"yyyy-MM-ddHH:mm:ss"];
8
9return[dateFormatterstringFromDate:detaildate];
10}

//时间转时间戳的方法:sendDate为NSDate类

NSString*timeSp=[NSStringstringWithFormat:@"%ld",(long)[sendDatetimeIntervalSince1970]];

//获取代表公历的NSCalendar对象
NSCalendar*gregorian=[[NSCalendaralloc]
initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
//获取当前日期
//定义一个时间字段的旗标，指定将会获取指定年、月、日、时、分、秒的信息
unsignedunitFlags=NSCalendarUnitYear|
NSCalendarUnitMonth|NSCalendarUnitDay|
NSCalendarUnitHour|NSCalendarUnitMinute|
NSCalendarUnitSecond|NSCalendarUnitWeekday;
//获取不同时间字段的信息
NSDateComponents*comp=[gregoriancomponents:unitFlags
fromDate:localeDate];
NSIntegeryear=comp.year;

//下面是可以获取的内容//
@propertyNSIntegerera;
@propertyNSIntegeryear;
@propertyNSIntegermonth;
@propertyNSIntegerday;
@propertyNSIntegerhour;
@propertyNSIntegerminute;
@propertyNSIntegersecond;
@propertyNSIntegernanosecondNS_AVAILABLE(10_7,5_0);
@propertyNSIntegerweekday;
@propertyNSIntegerweekdayOrdinal;
@propertyNSIntegerquarterNS_AVAILABLE(10_6,4_0);
@propertyNSIntegerweekOfMonthNS_AVAILABLE(10_7,5_0);
@propertyNSIntegerweekOfYearNS_AVAILABLE(10_7,5_0);
@propertyNSIntegeryearForWeekOfYearNS_AVAILABLE(10_7,5_0);