Add comment about 1956 Soviet book

* Makefile (UNUSUAL_OK_CHARSET): Add «, ».
* europe: Add comment (thanks to Marat Nigametzianov).

Makefile

@@ -416,9 +416,9 @@ SAFE_CHARSET=	$(SAFE_CHARSET1)$(SAFE_CHARSET2)$(SAFE_CHARSET3)
 SAFE_CHAR=	'[]'$(SAFE_CHARSET)'-]'
 
 # Non-ASCII non-letters that OK_CHAR allows, as these characters are
-# useful in commentary.  XEmacs 21.5.34 displays them correctly,
-# presumably because they are Latin-1.
-UNUSUAL_OK_CHARSET= °±½¾×
+# useful in commentary.  These all came from Latin-1, and so are likely
+# to be displayable even in editors with limited character sets.
+UNUSUAL_OK_CHARSET= «°±»½¾×
 
 # OK_CHAR matches any character allowed in the distributed files.
 # This is the same as SAFE_CHAR, except that UNUSUAL_OK_CHARSET and

europe

@@ -2429,6 +2429,20 @@ Zone Europe/Bucharest	1:44:24 -	LMT	1891 Oct
 # administratively part of Sakhalin oblast', they appear to have
 # remained on UTC+11 along with Magadan.
 
+# From Marat Nigametzianov (2018-07-16):
+# this is link to order from 1956 about timezone in USSR
+# http://astro.uni-altai.ru/~orion/blog/2011/11/novyie-granitsyi-chasovyih-poyasov-v-sssr/
+# From Paul Eggert (2018-07-16):
+# Perhaps someone could translate the above-mentioned link and use it
+# to correct our data for the ex-Soviet Union.  It cites the following:
+# «Поясное время и новые границы часовых поясов» / сост. П.Н. Долгов,
+# отв. ред. Г.Д. Бурдун - М: Комитет стандартов, мер и измерительных
+# приборов при Совете Министров СССР, Междуведомственная комиссия
+# единой службы времени, 1956 г.
+# This book looks like it would be a helpful resource for the Soviet
+# Union through 1956.  Although a copy was in the Scientific Library
+# of Tomsk State University, I have not been able to track down a copy nearby.
+
 # From Tim Parenti (2014-07-06):
 # The comments detailing the coverage of each Russian zone are meant to assist
 # with maintenance only and represent our best guesses as to which regions
@@ -2439,9 +2453,6 @@ Zone Europe/Bucharest	1:44:24 -	LMT	1891 Oct
 # future stability.  ISO 3166-2:RU codes are also listed for first-level
 # divisions where available.
 
-# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-
-
 # From Tim Parenti (2014-07-03):
 # Europe/Kaliningrad covers...
 # 39	RU-KGD	Kaliningrad Oblast