NSDateComponentsFormatter's stringFromDate(_, toDate:) returns nil

Originator:getaaron
Number:rdar://19903541 Date Originated:2/20/2015
Status:Open Resolved:
Product:iOS SDK Product Version:Xcode 6.3 (6D520o)
Classification:Serious Bug Reproducible:Always
 
Summary:
NSDateComponentsFormatter's stringFromDate(_, toDate:) returns nil when passed two dates

Steps to Reproduce:
let formatter = NSDateComponentsFormatter()
let referenceDate = NSDate(timeIntervalSinceReferenceDate: 0)
let intervalDate = NSDate(timeInterval: 3628810, sinceDate: referenceDate)
let string = formatter.stringFromDate(referenceDate, toDate: intervalDate)


Expected Results:
I'm expecting a string like "6w 0:00:10" to be returned.


Actual Results:
nil is returned.

Version:
Reproduces in both Xcode 6.1.1 (6A2008a) and Xcode 6.3 (6D520o)

Notes:
Different results depending on the value assigned to formatter.allowedUnits.

If  `.DayCalendarUnit | .HourCalendarUnit | .MinuteCalendarUnit | .SecondCalendarUnit` is assigned, it works as expected.

If `.WeekCalendarUnit` is assigned, I get the number 1.

If `.YearCalendarUnit` or `.MonthCalendarUnit` is included, I get this error:

"NSInvalidArgumentException", "Specifying positional units with gaps is ambiguous, and therefore unsupported"

Comments

Additional Notes

The documentation says "Default value is ... years | months | weeks | days | hours | minutes | seconds if passed an NSTimeInterval or pair of NSDates." which it's clearly not doing.

By getaaron at Feb. 20, 2015, 6:08 p.m. (reply...)

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