我需要使用日期时间和当前位置的纬度和经度来计算Nakshatra和Thithi 。
日期从
    NSDate *today = [NSDate date];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
 // display in 12HR/24HR (i.e. 11:25PM or 23:25) format according to User Settings
    [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
    NSString *currentTime = [dateFormatter stringFromDate:today];
    [dateFormatter release];
经度和纬度值来自NSLocationManager. 有人可以阐明数学计算吗?