[tz] "time zone" vs "timezone" in documentation

[Robert Elz]

Working out when an expression formed out of two words has turned into
a new word is always something of a black art - yet it happens all the time.

Consider cutthroat or bullshit - clearly words these days, but not always.
Or more relevantly perhaps, timecard, timepiece or timetable.

Whether timezone, timestamp, or filesystem have reached that state yet
or not isn't clear - personally, I think they have (and without any wishy
washy "a timezone is a technical thing in tzdb and time zone is an area
with a common offset from UTC (for some period)".

It is also worth noting that the way the transition happens, is for people
to simply start writing (and saying, though I think that's definitely
already happened for the cases in question) the word pair as a single
word and ignoring the "that's not correct" criticism. 

In my early schooldays (another one) I was taught that the digit '0' was
definitely not 'Oh' (that's a letter) and nor was it "zero" (that's American
invented nonsense) but a "nought".   I can't even imagine the last time I
heard anyone use that though (decades ago).  The language is continually
changing, and we all need to keep up, and not persist in "I was taught..."

kre