use integer;
use vars qw( $VERSION @ISA @EXPORT @EXPORT_OK );
-$VERSION = '1.12_01';
-$VERSION = eval $VERSION;
+$VERSION = '1.17';
+
@ISA = qw( Exporter );
@EXPORT = qw( timegm timelocal );
@EXPORT_OK = qw( timegm_nocheck timelocal_nocheck );
my $md = $MonthDays[$month];
++$md
- unless $month != 1 or $year % 4 or !( $year % 400 );
+ if $month == 1 && _is_leap_year( $year + 1900 );
croak "Day '$mday' out of range 1..$md" if $mday > $md or $mday < 1;
croak "Hour '$hour' out of range 0..23" if $hour > 23 or $hour < 0;
+ ( SECS_PER_DAY * $days );
}
+sub _is_leap_year {
+ return 0 if $_[0] % 4;
+ return 1 if $_[0] % 100;
+ return 0 if $_[0] % 400;
+
+ return 1;
+}
+
sub timegm_nocheck {
local $Options{no_range_check} = 1;
return &timegm;
sub timelocal {
my $ref_t = &timegm;
- my $loc_t = _timegm( localtime($ref_t) );
+ my $loc_for_ref_t = _timegm( localtime($ref_t) );
- # Is there a timezone offset from GMT or are we done?
- my $zone_off = $ref_t - $loc_t
- or return $loc_t;
-
- # This hack is needed to always pick the first matching time
- # during a DST change when time would otherwise be ambiguous
- $zone_off -= SECS_PER_HOUR if $ref_t >= SECS_PER_HOUR;
+ my $zone_off = $loc_for_ref_t - $ref_t
+ or return $loc_for_ref_t;
# Adjust for timezone
- $loc_t = $ref_t + $zone_off;
+ my $loc_t = $ref_t - $zone_off;
# Are we close to a DST change or are we done
- my $dst_off = $ref_t - _timegm( localtime($loc_t) )
- or return $loc_t;
+ my $dst_off = $ref_t - _timegm( localtime($loc_t) );
+
+ # If this evaluates to true, it means that the value in $loc_t is
+ # the _second_ hour after a DST change where the local time moves
+ # backward.
+ if ( ! $dst_off &&
+ ( ( $ref_t - SECS_PER_HOUR ) - _timegm( localtime( $loc_t - SECS_PER_HOUR ) ) < 0 )
+ ) {
+ return $loc_t - SECS_PER_HOUR;
+ }
# Adjust for DST change
$loc_t += $dst_off;
- return $loc_t if $dst_off >= 0;
+ return $loc_t if $dst_off > 0;
- # for a negative offset from GMT, and if the original date
- # was a non-extent gap in a forward DST jump, we should
- # now have the wrong answer - undo the DST adjust;
+ # If the original date was a non-extent gap in a forward DST jump,
+ # we should now have the wrong answer - undo the DST adjustment
my ( $s, $m, $h ) = localtime($loc_t);
$loc_t -= $dst_off if $s != $_[0] || $m != $_[1] || $h != $_[2];
=head1 DESCRIPTION
-These routines are the inverse of built-in perl functions localtime()
-and gmtime(). They accept a date as a six-element array, and return
-the corresponding time(2) value in seconds since the system epoch
-(Midnight, January 1, 1970 GMT on Unix, for example). This value can
-be positive or negative, though POSIX only requires support for
-positive values, so dates before the system's epoch may not work on
-all operating systems.
+This module provides functions that are the inverse of built-in perl
+functions C<localtime()> and C<gmtime()>. They accept a date as a
+six-element array, and return the corresponding C<time(2)> value in
+seconds since the system epoch (Midnight, January 1, 1970 GMT on Unix,
+for example). This value can be positive or negative, though POSIX
+only requires support for positive values, so dates before the
+system's epoch may not work on all operating systems.
It is worth drawing particular attention to the expected ranges for
-the values provided. The value for the day of the month is the actual
+the values provided. The value for the day of the month is the actual
day (ie 1..31), while the month is the number of months since January
-(0..11). This is consistent with the values returned from localtime()
-and gmtime().
+(0..11). This is consistent with the values returned from
+C<localtime()> and C<gmtime()>.
+
+=head1 FUNCTIONS
-The timelocal() and timegm() functions perform range checking on the
-input $sec, $min, $hour, $mday, and $mon values by default. If you
-are confident that your data is good, you can explicitly import the
-timelocal_nocheck() and timegm_nocheck() functions, which may provide
-a small performance improvement.
+This module exports two functions by default, C<timelocal()> and
+C<timegm()>.
+
+The C<timelocal()> and C<timegm()> functions perform range checking on
+the input $sec, $min, $hour, $mday, and $mon values by default.
+
+If you are working with data you know to be valid, you can speed your
+code up by using the "nocheck" variants, C<timelocal_nocheck()> and
+C<timegm_nocheck()>. These variants must be explicitly imported.
use Time::Local 'timelocal_nocheck';
# The 365th day of 1999
print scalar localtime timelocal_nocheck 0,0,0,365,0,99;
-Strictly speaking, the year should also be specified in a form
-consistent with localtime(), i.e. the offset from 1900. In order to
-make the interpretation of the year easier for humans, however, who
-are more accustomed to seeing years as two-digit or four-digit values,
-the following conventions are followed:
+If you supply data which is not valid (month 27, second 1,000) the
+results will be unpredictable (so don't do that).
+
+=head2 Year Value Interpretation
+
+Strictly speaking, the year should be specified in a form consistent
+with C<localtime()>, i.e. the offset from 1900. In order to make the
+interpretation of the year easier for humans, however, who are more
+accustomed to seeing years as two-digit or four-digit values, the
+following conventions are followed:
=over 4
=item *
Years greater than 999 are interpreted as being the actual year,
-rather than the offset from 1900. Thus, 1964 would indicate the year
+rather than the offset from 1900. Thus, 1964 would indicate the year
Martin Luther King won the Nobel prize, not the year 3864.
=item *
-Years in the range 100..999 are interpreted as offset from 1900,
-so that 112 indicates 2012. This rule also applies to years less than zero
-(but see note below regarding date range).
+Years in the range 100..999 are interpreted as offset from 1900, so
+that 112 indicates 2012. This rule also applies to years less than
+zero (but see note below regarding date range).
=item *
Years in the range 0..99 are interpreted as shorthand for years in the
rolling "current century," defined as 50 years on either side of the
-current year. Thus, today, in 1999, 0 would refer to 2000, and 45 to
-2045, but 55 would refer to 1955. Twenty years from now, 55 would
-instead refer to 2055. This is messy, but matches the way people
-currently think about two digit dates. Whenever possible, use an
+current year. Thus, today, in 1999, 0 would refer to 2000, and 45 to
+2045, but 55 would refer to 1955. Twenty years from now, 55 would
+instead refer to 2055. This is messy, but matches the way people
+currently think about two digit dates. Whenever possible, use an
absolute four digit year instead.
=back
The scheme above allows interpretation of a wide range of dates,
particularly if 4-digit years are used.
-Please note, however, that the range of dates that can be actually be
-handled depends on the size of an integer (time_t) on a given
+=head2 Limits of time_t
+
+The range of dates that can be actually be handled depends on the size
+of C<time_t> (usually a signed integer) on the given
platform. Currently, this is 32 bits for most systems, yielding an
approximate range from Dec 1901 to Jan 2038.
-Both timelocal() and timegm() croak if given dates outside the
+Both C<timelocal()> and C<timegm()> croak if given dates outside the
supported range.
=head2 Ambiguous Local Times (DST)
Because of DST changes, there are many time zones where the same local
-time occurs for two different GMT times on the same day. For example,
+time occurs for two different GMT times on the same day. For example,
in the "Europe/Paris" time zone, the local time of 2001-10-28 02:30:00
can represent either 2001-10-28 00:30:00 GMT, B<or> 2001-10-28
01:30:00 GMT.
=head2 Non-Existent Local Times (DST)
When a DST change causes a locale clock to skip one hour forward,
-there will be an hour's worth of local times that don't exist. Again,
+there will be an hour's worth of local times that don't exist. Again,
for the "Europe/Paris" time zone, the local clock jumped from
2001-03-25 01:59:59 to 2001-03-25 03:00:00.
-If the timelocal() function is given a non-existent local time, it
+If the C<timelocal()> function is given a non-existent local time, it
will simply return an epoch value for the time one hour later.
=head2 Negative Epoch Values
-Negative epoch (time_t) values are not officially supported by the
-POSIX standards, so this module's tests do not test them. On some
-systems, they are known not to work. These include MacOS (pre-OSX)
-and Win32.
+Negative epoch (C<time_t>) values are not officially supported by the
+POSIX standards, so this module's tests do not test them. On some
+systems, they are known not to work. These include MacOS (pre-OSX) and
+Win32.
On systems which do support negative epoch values, this module should
be able to cope with dates before the start of the epoch, down the
=head1 IMPLEMENTATION
These routines are quite efficient and yet are always guaranteed to
-agree with localtime() and gmtime(). We manage this by caching the
-start times of any months we've seen before. If we know the start
+agree with C<localtime()> and C<gmtime()>. We manage this by caching
+the start times of any months we've seen before. If we know the start
time of the month, we can always calculate any time within the month.
The start times are calculated using a mathematical formula. Unlike
-other algorithms that do multiple calls to gmtime().
+other algorithms that do multiple calls to C<gmtime()>.
-timelocal() is implemented using the same cache. We just assume that
-we're translating a GMT time, and then fudge it when we're done for
-the timezone and daylight savings arguments. Note that the timezone
-is evaluated for each date because countries occasionally change their
-official timezones. Assuming that localtime() corrects for these
-changes, this routine will also be correct.
+The C<timelocal()> function is implemented using the same cache. We
+just assume that we're translating a GMT time, and then fudge it when
+we're done for the timezone and daylight savings arguments. Note that
+the timezone is evaluated for each date because countries occasionally
+change their official timezones. Assuming that C<localtime()> corrects
+for these changes, this routine will also be correct.
=head1 BUGS
=head1 SUPPORT
Support for this module is provided via the datetime@perl.org email
-list. See http://lists.perl.org/ for more details.
+list. See http://lists.perl.org/ for more details.
-Please submit bugs using the RT system at rt.cpan.org, or as a last
-resort, to the datetime@perl.org list.
+Please submit bugs to the CPAN RT system at
+http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Time-Local or via email
+at bug-time-local@rt.cpan.org.
=head1 AUTHOR
Rolsky, <autarch@urth.org>.
=cut
-
projects / p5sagit/p5-mst-13.2.git / blobdiff