Getting precise timestamps and differences in time

Question

What is the best way to get timestamps in iOS and then calculate time on e.g. 2 timestamps? What data type is it? and if it is NSTimeInterval, can this value be stored in a dictionary that is then written to a plist? JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

Unix time is best. Indeed, using NSTimeInterval makes it really easy to calculate dates. It's just a double, so: NSDate *startDate; NSDate *endDate; NSTimeInterval interval; // assuming start and end dates have a value interval = [endDate timeIntervalSince1970] - [startDate timeIntervalSince1970]; When the dictionary is to be serialised or written to a document database like Couch or Mongo, I usually record the time interval as a NSString: NSDate *dateToStore; // assume dateToStore has a value NSTimeInterval aTimeInterval = [dateToStore timeIntervalSince1970]; NSString *aStringObject = [NSString stringwithFormat:@"%f", aTimeInterval]; NSDictionary *aDict = [NSDictionary dictionaryWithObject:dateAsString forKey:@"aKey"]; Then you can just read it back again when you use the dictionary object: NSTimeInterval newTimeInterval = [[aDict valueForKey:"aKey"] doubleValue]; NSDate *retreivedDate = [NSDate dateWithTimeIntervalSince1970:newTimeInterval]; If it's going to plist, you can just skip the string conversion.