The word "data" is plural.

NEWS

@@ -427,7 +427,7 @@ Release 2014a - 2014-03-07 23:30:29 -0800
 
       Microsoft has some support for tz database names.
 
-      CLDR data is available in both XML and JSON form.
+      CLDR data are available in both XML and JSON form.
 
       Mention Maggiolo's map of solar vs standard time.
       (Thanks to Arthur David Olson.)
@@ -671,8 +671,8 @@ Release 2013e - 2013-09-19 23:50:04 -0700
     some errors before 1947.
 
     Some zones have been turned into links, when they differ from
-    existing zones only in older data that was likely invented or that
-    differs only in LMT or transition from LMT.  These changes affect
+    existing zones only in older data that were likely invented or that
+    differ only in LMT or transitions from LMT.  These changes affect
     only time stamps before 1943.  The affected zones are:
     Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
     America/Grenada, America/Guadeloupe, America/Marigot,
@@ -2543,7 +2543,7 @@ Release 94h - 1994-12-10 12:51:14 -0500
 	data files.
 
   Think of this as "TZ Classic" - the software has been set up not to break if
-  universal time shows up in its input, and the data has been left as is so as
+  universal time shows up in its input, and the data have been left as is so as
   not to break existing implementations.
 
 
@@ -2623,7 +2623,7 @@ Release 93f - 1993-10-15 12:27:46 -0400
 
 Release 93e - 1993-09-05 21:21:44 -0400
 
-  There's updated data for Israel, England, and Kwajalein; there's
+  There are updated data for Israel, England, and Kwajalein; there's
   also an update to "zdump" to cope with Kwajalein's 24-hour jump.
   Thanks to Paul Eggert and Peter Ilieve for the changes.
 

Theory

@@ -254,7 +254,7 @@ Errors in the tz database arise from many sources:
    the current single entry for France would need to split into dozens
    of entries, perhaps hundreds.
 
- * Most of the pre-1970 data comes from unreliable sources, often
+ * Most of the pre-1970 data come from unreliable sources, often
    astrology books that lack citations and whose compilers evidently
    invented entries when the true facts were unknown, without
    reporting which entries were known and which were invented.
@@ -283,7 +283,7 @@ Errors in the tz database arise from many sources:
    Caledonian railways.
 
  * The tz database does not record the earliest time for which a
-   zone's data is thereafter valid for every location in the region.
+   zone's data are thereafter valid for every location in the region.
    For example, Europe/London is valid for all locations in its
    region after GMT was made the standard time, but the date of
    standardization (1880-08-02) is not in the tz database, other than

africa

@@ -1,7 +1,7 @@
 # This file is in the public domain, so clarified as of
 # 2009-05-17 by Arthur David Olson.
 
-# This data is by no means authoritative; if you think you know better,
+# This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.

asia

@@ -1,7 +1,7 @@
 # This file is in the public domain, so clarified as of
 # 2009-05-17 by Arthur David Olson.
 
-# This data is by no means authoritative; if you think you know better,
+# This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
@@ -386,7 +386,7 @@ Rule	PRC	1987	1991	-	Apr	Sun>=10	0:00	1:00	D
 # Xujiahui Observatory was under French control and stuck with UT+8.
 #
 # In earlier versions of this file, China had many separate Zone entries, but
-# this was based on what was apparently incorrect data in Shanks & Pottenger.
+# this was based on what were apparently incorrect data in Shanks & Pottenger.
 # This has now been simplified to the two entries Asia/Shanghai and
 # Asia/Urumqi, with the others being links for backward compatibility.
 # Proposed in 1918 and theoretically in effect until 1949 (although in practice
@@ -2630,8 +2630,7 @@ Rule	Syria	2007	only	-	Nov	 Fri>=1	0:00	0	-
 
 # From Stephen Colebourne (2008-03-17):
 # For everyone's info, I saw an IATA time zone change for [Syria] for
-# this month (March 2008) in the last day or so...This is the data IATA
-# are now using:
+# this month (March 2008) in the last day or so....
 # Country     Time Standard   --- DST Start ---   --- DST End ---  DST
 # Name        Zone Variation   Time    Date        Time    Date
 # Variation

australasia

@@ -761,7 +761,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 
 # NOTES
 
-# This data is by no means authoritative; if you think you know better,
+# This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.

europe

@@ -1,7 +1,7 @@
 # This file is in the public domain, so clarified as of
 # 2009-05-17 by Arthur David Olson.
 
-# This data is by no means authoritative; if you think you know better,
+# This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.

newctime.3

@@ -235,7 +235,7 @@ time(2),
 tzfile(5)
 .SH NOTES
 The return values point to static data;
-the data is overwritten by each call.
+the data are overwritten by each call.
 The
 .B tm_zone
 field of a returned

northamerica

@@ -3,7 +3,7 @@
 
 # also includes Central America and the Caribbean
 
-# This data is by no means authoritative; if you think you know better,
+# This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.

southamerica

@@ -1,7 +1,7 @@
 # This file is in the public domain, so clarified as of
 # 2009-05-17 by Arthur David Olson.
 
-# This data is by no means authoritative; if you think you know better,
+# This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.

tzfile.5

@@ -25,14 +25,14 @@ The number of UT/local indicators stored in the file.
 The number of standard/wall indicators stored in the file.
 .TP
 .I tzh_leapcnt
-The number of leap seconds for which data is stored in the file.
+The number of leap seconds for which data are stored in the file.
 .TP
 .I tzh_timecnt
-The number of "transition times" for which data is stored
+The number of "transition times" for which data are stored
 in the file.
 .TP
 .I tzh_typecnt
-The number of "local time types" for which data is stored
+The number of "local time types" for which data are stored
 in the file (must not be zero).
 .TP
 .I tzh_charcnt

zic.8

@@ -72,7 +72,7 @@ no leap second information appears in output files.
 Be more verbose, and complain about the following situations:
 .RS
 .PP
-The input data specifies a link to a link.
+The input specifies a link to a link.
 .PP
 A year that appears in a data file is outside the range
 of years representable by