HoursMinutesSeconds

Part of a program that I’m working on calculates an amount of time in seconds. I need to know what the best way is to calculate and format the time in Hours:Minutes:Seconds (00:00:00) format. http://goo.gl/OeSCu

– JacobHazelgrove

Maybe you could do something like:

NSCalendarDate *date=[NSCalendarDate dateWithTimeIntervalSince1970:numberOfSeconds];

and then use a NSCalendarDate method on date such as

-years:months:days:hours:minutes:seconds:sinceDate: (with the last parameter being [NSDate dateWithTimeIntervalSince1970:0])

-descriptionWithCalendarFormat:

I am not sure if this is the answer to your question, but would it not be easier to use a NSDateFormatter on an interface object or simply splice together a string [NSString stringByAppendingString:@””] if needed?

– MatPeterson

I got a similar problem, and instead of trying to include formatters (which may be a good solution), I simply created a formatted string of my own :

int h,m,s;           // Stand for hours, minutes, seconds
[theField setStringValue:[NSString stringWithFormat:@"%i : %i : %i", h, m, s]];

I’m sure there are some other ways to do it, but this one is quite easy. Note that in my piece of programming, I didn’t think about getting the values to calculate them or make a NSDate with them. If it’s what you want to do, this might be a little more complicated…

– Trax

Yeah my main problem is taking seconds and computing it into hours, minutes, and seconds. For now I’m just going to have three fields to output the time:

[theHoursField setIntValue:hours];
[theMinutesField setIntValue:minutes];
[theSecondsField setIntValue:seconds];

– JacobHazelgrove

With the modulo operator (%), it’s fairly simple to get hours and minutes from the total amount of seconds. Assuming you have a variable called totalSeconds, for example :

long totalSeconds;

hours = (totalSeconds / 3600); // returns number of whole hours fitted in totalSecs minutes = ((totalSeconds / 60) - hours*60); // Whole minutes

// Here we can use modulo to get num secs NOT fitting in whole minutes (60 secs) seconds = (totalSeconds % 60)

[theField setStringValue:[NSString stringWithFormat:@”%i : %i : %i”, hours, minutes, seconds]];

– Trax (Hmm… I’m not sure I like this, Trax; you rewrote the text above the code, but it was I that wrote the example code, and originally, there was a “– EnglaBenny” note here! – EnglaBenny)

Thanks guys, I had to re-work a bit of my other code for it to work, but it works great.

– JacobHazelgrove

What about leap seconds though?

For my purpose, leap seconds will never come into play. The app deals mostly with hours and anything less, and so being accurate out to years, would be major overkill.

JacobHazelgrove

We’re actually overdue for another leap-second. You might want to consider it. Maybe. – DustinVoss

I am using it for an app that figures roughly how long it will take to download a file. Now unless you are downloading a few hundred terabytes at 2kb/sec, there is no need for leap-seconds.

JacobHazelgrove

You’re clearly not pedantic enough to be a RealProgrammer ;) (Ever read RealProgrammersDontUsePascal? It’s in the jargon file, I believe, and is quite amusing.) – RobRix

I did a little test and a few hundred (300) terabytes at 2kb/sec would come out to (APPROXIMATELY) 64 years, 240 days, 5 hours, 14 minutes, and 7 seconds. Not including leap seconds.

– JacobHazelgrove

And you don’t want the increased precision in your download-figuring program? Psh! :) – RobRix

There was a slight error (16282 years) in the figures above. Fixed now.

– JacobHazelgrove

Ya’ll provided this here code above:

long totalSeconds;

hours = (totalSeconds / 3600); // returns number of whole hours fitted in totalSecs minutes = ((totalSeconds / 60) - hours*60); // Whole minutes

// Here we can use modulo to get num secs NOT fitting in whole minutes (60 secs) seconds = (totalSeconds % 60)

[theField setStringValue:[NSString stringWithFormat:@”%i : %i : %i”, hours, minutes, seconds]];

What would a person have to add/modify to have it handle days? (Mainly that there calculation)

– Lester

Change this:

[theField setStringValue:[NSString stringWithFormat:@”%i : %i : %i”, hours, minutes, seconds]];

to this:

[theField setStringValue:[NSString stringWithFormat:@”%i : %i : %i : %i”, days, hours, minutes, seconds]];

You will have to change that, but I dont know about the calculation.

Insert this after the original hour calculation:

days = hours / 24; hours %= 24;

–EnglaBenny

I’m a newbie to cocoa but i haven’t been able to figure out for the life of me how to subtract 2 dates and then display the results ie 10/17/2003 12:49:00 PM - Now then display the results as a formatted date like 00:00:00:00

–Chewtoy

%%C%% NSDate *fromDate, *toDate; . . . NSTimeInterval seconds = [toDate timeIntervalSinceDate:fromDate]; %%/C%% You can then easily calculate hours/minutes/seconds or whatever for input to NSString’s +stringWithFormat: or -initWithFormat:

CocoaDev

–Chewtoy