1.NSString 轉(zhuǎn) NSDate格式：

- (NSDate *)stringToDate:(NSSTring *)str {
     NSDateFormatter *dateFormatter = [NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM"];//自己改變?nèi)掌诟袷?    [dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:8]];//解決八小時(shí)時(shí)差的問(wèn)題
    NSDate *myDate = [dateFormatter dateFromString:str];
    return myDate;
}

2.NSDate 轉(zhuǎn) NSString格式：

- (NSString *)dateToString:(NSDate *)dateTime {
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM"];//自己改變?nèi)掌诟袷?    NSString *strDate = [dateFormatter stringFromDate:dateTime];
    return strDate;
}

3.兩個(gè)相同的時(shí)間日期格式相減：

- (double)dateSecondDifference:(NSString *)startTime endTime:(NSString *)endTime {
    NSDateFormatter *date = [[NSDateFormatter alloc]init];
    [date setDateFormat:@"yyyyMMddHHmmss"];
    NSDate *startD =[date dateFromString:startTime];
    NSDate *endD = [date dateFromString:endTime];
    NSTimeInterval start = [startD timeIntervalSince1970]*1;
    NSTimeInterval end = [endD timeIntervalSince1970]*1;
    NSTimeInterval value = end - start;
    float timeF = (float)value;
    return timeF;
}

4.一個(gè)是日期格式，獲取多少秒之后的日期寫(xiě)法：

- (NSString *)dateAddTime:(NSString *)startTime endTime:(NSString *)endTime {
    NSDateFormatter *date = [[NSDateFormatter alloc]init];
    [date setDateFormat:@"yyyyMMddHHmmss"];
    NSDate *startD =[date dateFromString:startTime];
    NSDate *endD = [date dateFromString:endTime];
    NSTimeInterval start = [startD timeIntervalSince1970]*1;
    NSTimeInterval end = [endD timeIntervalSince1970]*1;
    NSTimeInterval value = start + end;
    NSString *timDD = [self timeDateFormatted:value];
    return timDD;
}

- (NSString *)timeDateFormatted:(NSInteger)totalSeconds

{
    NSDate *date = [[NSDate alloc] initWithTimeIntervalSince1970:totalSeconds];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    dateFormatter.dateFormat = @"yyyyMMddHHmmss";
    return [dateFormatter stringFromDate:date];
}

5.日期格式返回時(shí)分秒：

-(NSString *)getSSFromSS:(NSString *)totalTime{
    NSInteger seconds = [totalTime integerValue];
    //format of minute
    NSString *str_minute = [NSString stringWithFormat:@"%02ld",(seconds%3600)/60];
    //format of second
    NSString *str_second = [NSString stringWithFormat:@"%02ld",seconds%60];
    //format of time
    NSString *format_time = [NSString stringWithFormat:@"%@:%@",str_minute,str_second];
    return format_time; 
}

6.獲取當(dāng)前時(shí)間字符串格式:

- (NSString *)getGpsCurrentTime:(NSDate *)date {
    
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyyMMddHHmmss"];
    NSString *dateTime = [formatter stringFromDate:date];
    return dateTime;
}

7.獲取當(dāng)前時(shí)間date格式钧汹，轉(zhuǎn)8小時(shí)制:

- (NSDate *)getCurrenDate {  
    NSDate *date = [NSDate date];
    NSTimeZone *zone = [NSTimeZone systemTimeZone];
    NSInteger interval = [zone secondsFromGMTForDate: date];
    NSDate *localeDate = [date  dateByAddingTimeInterval: interval];
    return localeDate;
}