String from an NSDate in the form of "2 months ago"

DateString.m

- (NSString *)relativeDateStringFromDate:(NSDate *)date
{
	NSDate *now = [NSDate date];
	if ([now laterDate:date] == date)
		return nil; //dates in the future are not supported
	NSInteger years = [now yearsSinceDate:date];
	NSInteger months = [now monthsSinceDate:date];
	NSInteger weeks = [now weeksSinceDate:date];
	NSInteger days = [now daysSinceDate:date];
	NSInteger hours = [now hoursSinceDate:date];
	NSInteger minutes = [now minutesSinceDate:date];
	NSInteger seconds = [now secondsSinceDate:date];
	if (years > 0)
	{
		if (years == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commentyearago",nil),years];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commentyearsago",nil),years];
	} else if (months > 0)
	{
		if (months == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commentmonthago",nil),months];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commentmonthsago",nil),months];
	} else if (weeks > 0)
	{
		if (weeks == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commentweekago",nil),weeks];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commentweeksago",nil),weeks];
	} else if (days > 0)
	{
		if (days == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commentdayago",nil),days];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commentdaysago",nil),days];
	} else if (hours > 0)
	{
		if (hours == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commenthourago",nil),hours];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commenthoursago",nil),hours];
	} else if (minutes > 0)
	{
		if (minutes == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commentminuteago",nil),minutes];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commentminutesago",nil),minutes];
	} else if (seconds > 0)
	{
		if (seconds == 1)
			return [NSString stringWithFormat:NSLocalizedString(@"commentsecondago",nil),seconds];
		else
			return [NSString stringWithFormat:NSLocalizedString(@"commentsecondsago",nil),seconds];
	} else
		return NSLocalizedString(@"justnowcomment",nil);
	
	return @"";
}

Localizable.strings

"commentyearago" = "%ld year ago";
"commentyearsago" = "%ld years ago";
"commentmonthago" = "%ld month ago";
"commentmonthsago" = "%ld months ago";
"commentweekago" = "%ld week ago";
"commentweeksago" = "%ld weeks ago";
"commentdayago" = "%ld day ago";
"commentdaysago" = "%ld days ago";
"commenthourago" = "%ld hour ago";
"commenthoursago" = "%ld hours ago";
"commentminuteago" = "%ld minute ago";
"commentminutesago" = "%ld minutes ago";
"commentsecondago" = "%ld second ago";
"commentsecondsago" = "%ld seconds ago";
"justnowcomment" = "just now";