* zdump.8, NEWS: Document the gmtoff=N output.

NEWS

@@ -44,6 +44,8 @@ Unreleased, experimental changes
 
   Changes affecting documentation and commentary
 
+    zdump's gmtoff=N output is now documented.
+
     zdump -c's treatment of years is now documented to use the
     Gregorian calendar and Universal Time without leap seconds,
     and its behavior at cutoff boundaries is now documented better.

zdump.8

@@ -30,12 +30,17 @@ the time one day after the lowest possible time value,
 the times both one second before and exactly at
 each detected time discontinuity,
 the time at one day less than the highest possible time value,
-and the time at the highest possible time value,
-Each line ends with
-.B isdst=1
-if the given time is Daylight Saving Time or
-.B isdst=0
-otherwise.
+and the time at the highest possible time value.
+Each line is followed by
+.BI isdst= D
+where
+.I D
+is 1 if the given time is Daylight Saving Time and is 0 otherwise.
+Each line is also followed by
+.BI gmtoff= N
+if the given local time is known to be
+.I N
+seconds east of Greenwich.
 .TP
 .B \*-V
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