@findex first @r{in date strings}
@findex next @r{in date strings}
@findex last @r{in date strings}
-A few numbers may be written out in words in most contexts. This is
+A few ordinal numbers may be written out in words in some contexts. This is
most useful for specifying day of the week items or relative items (see
-below). Here is the list: @samp{first} for 1, @samp{next} for 2,
-@samp{third} for 3, @samp{fourth} for 4, @samp{fifth} for 5,
+below). Among the most commonly used ordinal numbers, the word
+@samp{last} stands for @math{-1}, @samp{this} stands for 0, and
+@samp{first} and @samp{next} both stand for 1. Because the word
+@samp{second} stands for the unit of time there is no way to write the
+ordinal number 2, but for convenience @samp{third} stands for 3,
+@samp{fourth} for 4, @samp{fifth} for 5,
@samp{sixth} for 6, @samp{seventh} for 7, @samp{eighth} for 8,
@samp{ninth} for 9, @samp{tenth} for 10, @samp{eleventh} for 11 and
-@samp{twelfth} for 12. Also, @samp{last} means exactly @math{-1}.
+@samp{twelfth} for 12.
@cindex months, written-out
When a month is written this way, it is still considered to be written
The time may alternatively be followed by a time zone correction,
expressed as @samp{@var{s}@var{hh}@var{mm}}, where @var{s} is @samp{+}
or @samp{-}, @var{hh} is a number of zone hours and @var{mm} is a number
-of zone minutes. When a time zone correction is given this way, it
+of zone minutes. You can also separate @var{hh} from @var{mm} with a colon.
+When a time zone correction is given this way, it
forces interpretation of the time relative to
Coordinated Universal Time (@sc{utc}), overriding any previous
-specification for the time zone or the local time zone. The @var{minute}
+specification for the time zone or the local time zone. For example,
+@samp{+0530} and @samp{+05:30} both stand for the time zone 5.5 hours
+ahead of @sc{utc} (e.g., India). The @var{minute}
part of the time of day may not be elided when a time zone correction
is used. This is the best way to specify a time zone correction by
fractional parts of an hour.
non-daylight-saving time zone by the string @samp{DST} in a separate
word (that is, separated by some white space), the corresponding
daylight saving time zone may be specified.
+Alternatively, a non-daylight-saving time zone can be followed by a
+time zone correction, to add the two values. This is normally done
+only for @samp{UTC}; for example, @samp{UTC+05:30} is equivalent to
+@samp{+05:30}.
Time zone items other than @samp{UTC} and @samp{Z}
are obsolescent and are not recommended, because they