Una vecchia domanda, ma per chi si imbatte in questo, controlla NSDateComponentsFormatter
.
Per esempio, ecco un metodo NSDate
categoria dal mio DejalFoundationCategories progetto open source:
+ (NSString *)dejal_relativeStringForTimeInterval:(NSTimeInterval)timeInterval style:(NSDateComponentsFormatterUnitsStyle)unitsStyle maximumUnits:(NSInteger)maximumUnits keepZero:(BOOL)keepZero defaultValue:(NSString *)defaultValue;
{
// If more than 10 years, assume distant past or future:
if (abs(timeInterval) > 60 * 60 * 24 * 365 * 10)
{
return defaultValue;
}
NSDateComponentsFormatter *formatter = [NSDateComponentsFormatter new];
formatter.unitsStyle = unitsStyle;
formatter.maximumUnitCount = maximumUnits;
if (keepZero)
{
formatter.zeroFormattingBehavior = NSDateComponentsFormatterZeroFormattingBehaviorDropLeading | NSDateComponentsFormatterZeroFormattingBehaviorDropMiddle;
}
else
{
formatter.zeroFormattingBehavior = NSDateComponentsFormatterZeroFormattingBehaviorDropAll;
}
return [formatter stringFromTimeInterval:timeInterval];
}
Date un'occhiata a NSDateFormatter: https://developer.apple.com/library/mac/documentation/Cocoa/Reference /Foundation/Classes/NSDateFormatter_Class/Reference/Reference.html –