Clearify our timezone offsets are in seconds

Fixes #1446

Author: zoffixznet

doc/Language/variables.pod6

@@ -1085,7 +1085,7 @@ X<|$*SPEC>X<|$*TMPDIR>X<|$*THREAD>X<|$*SCHEDULER>
     ------------------+--------------------------------------------
     $*REPO            | A variable holding information about modules installed/loaded
     ------------------+--------------------------------------------
-    $*TZ              | The system's local timezone.
+    $*TZ              | The system's local timezone offset, as the number of B<seconds> from GMT
     ------------------+--------------------------------------------
     $*CWD             | The Current Working Directory.
     ------------------+--------------------------------------------

doc/Type/DateTime.pod6

@@ -99,10 +99,12 @@ L<X::DateTime::TimezoneClash> is thrown.
 
 Defined as:
 
-    method now(:$timezone=$*TZ, :&formatter --> DateTime:D)
+    method now(:$timezone = $*TZ, :&formatter --> DateTime:D)
 
-Creates a new C<DateTime> object from the current system time, optionally with
-a different timezone than the default attached.
+Creates a new C<DateTime> object from the current system time. A custom
+L<formatter> and L<timezone> can be provided. The C<:$timezone> is 
+the offset B<in seconds> from L<GTM|https://en.wikipedia.org/wiki/Greenwich_Mean_Time>
+and defaults to the value of L«C<$*TZ> variable|/language/variables#index-entry-%24*TZ».
 
     say DateTime.now;
 
@@ -183,7 +185,7 @@ Defined as:
 
     method timezone(DateTime:D: --> Int:D)
 
-Returns the time zone in seconds as an offset from UTC.
+Returns the time zone B<in seconds> as an offset from UTC.
 
     say DateTime.new('2015-12-24T12:23:00+0200').timezone;          # OUTPUT: «7200␤»
 
@@ -193,7 +195,7 @@ Defined as:
 
     method offset(DateTime:D: --> Int:D)
 
-Returns the time zone in seconds as an offset from UTC. This is an alias for
+Returns the time zone B<in seconds> as an offset from UTC. This is an alias for
 L<#method timezone>.
 
     say DateTime.new('2015-12-24T12:23:00+0200').offset;            # OUTPUT: «7200␤»
@@ -353,7 +355,8 @@ Defined as:
 
     method in-timezone(DateTime:D: $timezone = 0 --> DateTime:D)
 
-Returns a DateTime object for the same time, but in the specified time zone.
+Returns a DateTime object for the same time, but in the specified C<$timezone>, which is
+the offset B<in seconds> from L<GMT|https://en.wikipedia.org/wiki/Greenwich_Mean_Time>.
 
     say DateTime.new('2015-12-24T12:23:00Z').in-timezone(3600 + 1800); # OUTPUT: «2015-12-24T13:53:00+0130␤»
 
@@ -364,7 +367,7 @@ Defined as:
     method local(DateTime:D: --> DateTime:D)
 
 Returns a DateTime object for the same time, but in the local time zone
-(C<$*TZ>).
+(L«C<$*TZ>|/language/variables#index-entry-%24*TZ»).
 
     my $*TZ = -3600;
     say DateTime.new('2015-12-24T12:23:00+0200').local; # OUTPUT: «2015-12-24T09:23:00-0100␤»