fails:Time#strftime requires an argument
fails:Time#strftime should be able to show the timezone if available
fails:Time#strftime rounds an offset to the nearest second when formatting with %z
fails:Time#strftime with %N formats the nanoseconds of the second with %N
fails:Time#strftime with %N formats the nanoseconds of the second with %9N
fails:Time#strftime with %N formats the picoseconds of the second with %12N
