How I can convert milliseconds to minutes or hours, in Objective-C or C?
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1There's 1000 milliseconds in a second. There's 60 seconds in a minute. 966000 / 1000 => 966 / 60 => 16 minutes. – Marvo May 18 '11 at 21:18
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2Close-as-off-topic lacks as "belongs on math.stackexchange.com" option... – R.. GitHub STOP HELPING ICE May 18 '11 at 21:19
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possible duplicate of [Convert milliseconds to seconds in C.](http://stackoverflow.com/questions/1294885/convert-milliseconds-to-seconds-in-c) – jscs May 18 '11 at 21:27
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1@R: I think this would get closed there as "Off-topic: programming question." – jscs May 18 '11 at 21:27
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Are your seconds representing duration, or absolute time? Are you interested in correct handling of leap seconds? – Marc Mutz - mmutz May 18 '11 at 21:28
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1Not a real question?! It's a perfectly valid question. It's just a dupe. – jscs May 18 '11 at 23:56
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I believe Maxime wants to do this programmatically and it therefore is a valid question. – Eric Brotto Jul 08 '11 at 10:40
4 Answers
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Just use simple division. Use floating point numbers so that you don't lose precision from rounding.
float milliseconds = 966000.0;
float seconds = milliseconds / 1000.0;
float minutes = seconds / 60.0;
float hours = minutes / 60.0;
ughoavgfhw
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#define MSEC_PER_SEC 1000L
#define SEC_PER_MIN 60
#define MIN_PER_HOUR 60
int msec = 966000;
int min = msec / (MSEC_PER_SEC * SEC_PER_MIN);
int hr = min / (MIN_PER_HOUR);
makes
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@progrmr Descriptive, but not more, as you can assume these constants to NEVER change their values in a meaningful context. – Christian Rau May 18 '11 at 22:43
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1@Christian, magic numbers without a meaningful name are bad style, no matter if their values change in this universe or not. – makes May 18 '11 at 22:56
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sounds a bit like a joke but what the heck…
- divide by 60*1000… for minutes.
- divide by 60*60*1000… for hours.
the beauty of it it works in all programming languages.
machunter
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