diff --git a/db/Makefile b/db/Makefile
index 0da5f4c..44071f0 100644
--- a/db/Makefile
+++ b/db/Makefile
@@ -1,9 +1,10 @@
 TZDIR=tzdata
 TZ_FILES=$(addprefix $(TZDIR)/, africa antarctica asia australasia backward etcetera europe northamerica southamerica)
 
+tzout: DATE := $(shell date +%F)
 tzout: $(TZ_FILES)
 	TZ_VERSION=`perl -n -e 'm/^VERSION\s*=\s*(\S+)/ and print $$1;' $(TZDIR)/Makefile`; \
-	./tz-erl --version $$TZ_VERSION -o $@ $^
+	./tz-erl --version $$TZ_VERSION --date $(DATE) -o $@ $^
 
 $(TZ_FILES): $(TZDIR)
 
diff --git a/db/tz-erl b/db/tz-erl
index 4936553..3f41e21 100755
--- a/db/tz-erl
+++ b/db/tz-erl
@@ -145,15 +145,17 @@ sub process_data {
   }
 }
 
+# Converts an offset in the format "[+-]?HH:MM" or "[+-]?HH" into minutes.
+# For example, "2:00" -> 120, "-0:30" -> -30, "+5" -> 300.
 sub offset_minutes {
   my ($off, $adj) = @_;
 
   my $convert_offset = sub {
-    my $m = $_[0];
-    if ($m =~ m/^([\+\-]?)(?:(\d+):)?(\d+)$/) {
-      $m = (defined $2 ? $2 : 0) * MPH + $3;
-      if ($1 eq '-') { $m = -$m; }
-    }
+    $_[0] =~ m/^([\+\-]?)(\d+)(?::(\d+))?$/
+      or die "offset \"$_[0]\" did not match";
+    my $m = $2 * MPH;
+    if (defined $3) { $m += $3; }
+    if ($1 eq '-') { $m = -$m; }
     return $m;
   };
 
@@ -256,9 +258,13 @@ sub zone_line {
   # We ignore any zone line that has a definite until (end) time that
   # is in the past.
   if (defined $until) {
-    my $until_year = ($until =~ m/^(\d+)/)[0];
-    if ($until_year >= $current_year) {
-      die "until $until not handled";
+    my ($until_year, $until_month, $until_day) = split_ymd($until);
+    if (($until_year > $current_year) ||
+        (($until_year == $current_year) &&
+         (($until_month > $current_month) ||
+          (($until_month == $current_month) &&
+           ($until_day >= $current_day))))) {
+      "future until \"$until\" not handled";
     }
     return;
   }
@@ -286,7 +292,10 @@ sub zone_line {
     $rule1 = $rule2 = RULE_NULL;
   } elsif (scalar(@rules) == 1) {
     # One active rule.  This is a year that DST started or stopped
-    # being observed
+    # being observed.  erlang_localtime doesn't handle this.  If DST
+    # stopped being observed in this year, don't output a DST rule.
+    # If DST started being observed, do.  (Except that we don't handle
+    # this yet.)
     print STDERR Data::Dump::dump(\@rules), "\n";
     die "one rule for $name";
     $name1 = zonename($format, $rules[0]->[RULE_LETTERS], undef);
@@ -427,6 +436,23 @@ INIT {
   %dow_from_name= map { $dow_to_name[$_] => $_ } (0..$#dow_to_name);
 }
 
+sub split_ymd {
+  my ($ymd) = @_;
+  $ymd =~ m/^(\d+)(?:\s+(\w+)(?:\s+(\d+)))?/
+    or die "parse \"$ymd\" for ymd failed";
+  my $year = $1;
+  my $month = do {
+    if (defined $2) {
+      defined $mon_from_name{$2} or die "parse \"$ymd\" for month failed";
+      $mon_from_name{$2};
+    } else {
+      0
+    }
+  };
+  my $day = defined $3 ? $3 : 0;
+  return ($year, $month, $day);
+}
+
 sub on_to_day_of_month {
   my ($on, $year, $month) = @_;
 
diff --git a/include/tz_database.hrl b/include/tz_database.hrl
index 2539526..7e6ac2f 100644
--- a/include/tz_database.hrl
+++ b/include/tz_database.hrl
@@ -427,33 +427,33 @@
       {"Eire",{"GMT","GMT"},{"IST","IST"},0,60,{last,sun,mar},{1,0},{last,sun,oct},{2,0}},
       {"Etc/GMT",{"GMT","GMT"},undef,0,0,undef,{0,0},undef,{0,0}},
       {"Etc/GMT+0",{"GMT","GMT"},undef,0,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+1",{"GMT+1","GMT+1"},undef,-1,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+10",{"GMT+10","GMT+10"},undef,-10,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+11",{"GMT+11","GMT+11"},undef,-11,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+12",{"GMT+12","GMT+12"},undef,-12,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+2",{"GMT+2","GMT+2"},undef,-2,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+3",{"GMT+3","GMT+3"},undef,-3,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+4",{"GMT+4","GMT+4"},undef,-4,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+5",{"GMT+5","GMT+5"},undef,-5,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+6",{"GMT+6","GMT+6"},undef,-6,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+7",{"GMT+7","GMT+7"},undef,-7,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+8",{"GMT+8","GMT+8"},undef,-8,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT+9",{"GMT+9","GMT+9"},undef,-9,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+1",{"GMT+1","GMT+1"},undef,60,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+10",{"GMT+10","GMT+10"},undef,600,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+11",{"GMT+11","GMT+11"},undef,660,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+12",{"GMT+12","GMT+12"},undef,720,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+2",{"GMT+2","GMT+2"},undef,120,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+3",{"GMT+3","GMT+3"},undef,180,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+4",{"GMT+4","GMT+4"},undef,240,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+5",{"GMT+5","GMT+5"},undef,300,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+6",{"GMT+6","GMT+6"},undef,360,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+7",{"GMT+7","GMT+7"},undef,420,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+8",{"GMT+8","GMT+8"},undef,480,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT+9",{"GMT+9","GMT+9"},undef,540,0,undef,{0,0},undef,{0,0}},
       {"Etc/GMT-0",{"GMT","GMT"},undef,0,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-1",{"GMT-1","GMT-1"},undef,1,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-10",{"GMT-10","GMT-10"},undef,10,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-11",{"GMT-11","GMT-11"},undef,11,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-12",{"GMT-12","GMT-12"},undef,12,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-13",{"GMT-13","GMT-13"},undef,13,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-14",{"GMT-14","GMT-14"},undef,14,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-2",{"GMT-2","GMT-2"},undef,2,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-3",{"GMT-3","GMT-3"},undef,3,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-4",{"GMT-4","GMT-4"},undef,4,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-5",{"GMT-5","GMT-5"},undef,5,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-6",{"GMT-6","GMT-6"},undef,6,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-7",{"GMT-7","GMT-7"},undef,7,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-8",{"GMT-8","GMT-8"},undef,8,0,undef,{0,0},undef,{0,0}},
-      {"Etc/GMT-9",{"GMT-9","GMT-9"},undef,9,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-1",{"GMT-1","GMT-1"},undef,-60,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-10",{"GMT-10","GMT-10"},undef,-600,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-11",{"GMT-11","GMT-11"},undef,-660,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-12",{"GMT-12","GMT-12"},undef,-720,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-13",{"GMT-13","GMT-13"},undef,-780,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-14",{"GMT-14","GMT-14"},undef,-840,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-2",{"GMT-2","GMT-2"},undef,-120,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-3",{"GMT-3","GMT-3"},undef,-180,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-4",{"GMT-4","GMT-4"},undef,-240,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-5",{"GMT-5","GMT-5"},undef,-300,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-6",{"GMT-6","GMT-6"},undef,-360,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-7",{"GMT-7","GMT-7"},undef,-420,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-8",{"GMT-8","GMT-8"},undef,-480,0,undef,{0,0},undef,{0,0}},
+      {"Etc/GMT-9",{"GMT-9","GMT-9"},undef,-540,0,undef,{0,0},undef,{0,0}},
       {"Etc/GMT0",{"GMT","GMT"},undef,0,0,undef,{0,0},undef,{0,0}},
       {"Etc/Greenwich",{"GMT","GMT"},undef,0,0,undef,{0,0},undef,{0,0}},
       {"Etc/UCT",{"UCT","UCT"},undef,0,0,undef,{0,0},undef,{0,0}},
diff --git a/src/localtime.erl b/src/localtime.erl
index ea07769..d6f18ed 100644
--- a/src/localtime.erl
+++ b/src/localtime.erl
@@ -20,6 +20,7 @@
      ,get_timezone/1
      ,list_timezones/0
      ,adjust_datetime/2
+     ,fmt_shift/1
   ]).
 
 % utc_to_local(UtcDateTime, Timezone) -> LocalDateTime | [LocalDateTime, DstLocalDateTime] | {error, ErrDescr}
@@ -214,6 +215,8 @@ fmt_shift({'+', H, M}) ->
    H * 60 + M;
 fmt_shift({'-', H, M}) ->
    -(H * 60 + M);
+fmt_shift(0) ->
+   0;
 fmt_shift(Any) ->
    throw(Any).
 
@@ -231,14 +234,18 @@ tr_char([H|T], From, To, Acc) ->
    end.
 
 -define(SPACE_CHAR, 32).
-get_timezone_inner(TimeZone) ->
+get_timezone_inner(TimeZone) when is_binary(TimeZone) ->
+    get_timezone_inner(erlang:binary_to_list(TimeZone));
+get_timezone_inner(TimeZone) when is_list(TimeZone) ->
    TimeZoneNoSpaces = tr_char(TimeZone, ?SPACE_CHAR, $_),
    case dict:find(TimeZoneNoSpaces, ?tz_index)  of
       error ->
          TimeZoneNoSpaces;
       {ok, [TZName | _]} ->
             TZName
-   end.
+   end;
+get_timezone_inner(_) ->
+    throw({error, "Timezone should be string/binary"}).
 
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").