patch to zic.8 to document format of UNTIL field

[Paul Eggert]

   From: "Rob Jones 4-6597 MR Sys" <jones at mr.med.ge.com>
   Date: Tue, 8 Oct 1996 12:23:18 -0500

   In the tzdata files when the UNTIL field is just a year (without a
   month day) specified, does that mean up to and including that year,
   or just up to ?

Somehow that didn't get documented.  Here's a draft patch.

In practice I use vague dates like `1967' when I don't know
exactly when the rules changed, and a more precise time stamp
like `1967 Jan 1 00:00' if I know that's the exact time --
even though both inputs mean the same thing to `zic'.

===================================================================
RCS file: RCS/zic.8,v
retrieving revision 1995.7
retrieving revision 1995.7.1.1
diff -c -r1995.7 -r1995.7.1.1
*** zic.8	1995/10/30 14:58:15	1995.7
--- zic.8	1996/10/08 18:31:38	1995.7.1.1
***************
*** 304,309 ****
--- 304,312 ----
  If this is specified,
  the time zone information is generated from the given GMT offset
  and rule change until the time specified.
+ The month, day, and time of day have the same format as the IN, ON, and AT
+ columns of a rule; trailing columns can be omitted, and default to the
+ earliest possible value for the missing columns.
  .IP
  The next line must be a
  .q continuation