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Time-Zone-Olson-0.09
River stage one • 1 direct dependent • 1 total dependent
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/ Time::Zone::Olson

NAME

Time::Zone::Olson - Provides an interface to the Olson timezone database

VERSION

Version 0.09

SYNOPSIS

    use Time::Zone::Olson();

    my $time_zone = Time::Zone::Olson->new({ timezone => 'Australia/Melbourne' }); # set timezone at creation time
    my $now = $time_zone->time_local($seconds, $minutes, $hours, $day, $month, $year); # convert from Australia/Melbourne time
    foreach my $area ($time_zone->areas()) {
        foreach my $location ($time_zone->locations($area)) {
            $time_zone->timezone("$area/$location");
            print scalar $time_zone->local_time($now); # output time in $area/$location local time
            warn scalar localtime($now) . " log message for sysadmin"; # but log in system local time
        }
    }

DESCRIPTION

Time::Zone::Olson is intended to provide a simple interface to the Olson database that is available on most UNIX systems. It provides an interface to list common time zones, such as Australia/Melbourne that are stored in the zone.tab file, and localtime/Time::Local::timelocal replacements to translate times to and from the users timezone, without changing the timezone used by Perl. This allows logging/etc to be conducted in the system's local time.

Time::Zone::Olson was designed to produce the same result as a 64bit copy of the date(1) command.

SUBROUTINES/METHODS

new

Time::Zone::Olson->new() will return a new timezone object. It accepts a hash reference as a parameter with an optional timezone key, which contains an Olson timezone value, such as 'Australia/Melbourne'. The hash reference also allows a directory key, with the file system location of the Olson timezone database as a value.

Both of these parameters default to $ENV{TZ} and $ENV{TZDIR} respectively.

areas

The areas() object method will return a list of the areas (such as Asia, Australia, Africa, America, Europe) from the zone.tab file. The areas will be sorted alphabetically.

locations

The locations($area) object method will return a list of the locations (such as Melbourne, Perth, Hobart) for a specified area from the zone.tab file. The locations will be sorted alphabetically.

comment

The comment($timezone) object method will return the matching comment from the zone.tab file for the timezone parameter. For example, if "Australia/Melbourne" was passed as a parameter, the "comment" function would return "Victoria"

directory

This object method can be used to get or set the root directory of the Olson database, usually located at /usr/share/zoneinfo.

timezone

This object method can be used to get or set the timezone, which will affect all future calls to "local_time" or "time_local". The parameter for this method should be in the Olson format of a timezone, such as "Australia/Melbourne".

equiv

This object method takes a timezone name as a parameter. It then compares the transition times and offsets for the currently set timezone to the transition times and offsets for the specified timezone and returns true if they match exactly from the current time. The second optional parameter can specify the start time to use when comparing the two time zones.

offset

This object method can be used to get or set the offset for all "local_time" or "time_local" calls. The offset should be specified in minutes from GMT.

area

This object method will return the area component of the current timezone, such as Australia

location

This object method will return the location component of the current timezone, such as Melbourne

local_offset

This object method takes the same arguments as localtime but returns the appropriate offset from GMT in minutes. This can to used as a offset parameter to a subsequent call to Time::Zone::Olson.

local_time

This object method has the same signature as the 64 bit version of the localtime function. That is, it accepts up to a 64 bit signed integer as the sole argument and returns the (seconds, minutes, hours, day, month, year, wday, yday, isdst) definition for the timezone for the object. The timezone used to calculate the local time may be specified as a parameter to the "new" method or via the "timezone" method.

time_local

This object method has the same signature as the 64 bit version of the Time::Local::timelocal function. That is, it accepts (seconds, minutes, hours, day, month, year, wday, yday, isdst) as parameters in a list and returns the correct UNIX time in seconds according to the current timezone for the object. The timezone used to calculate the local time may be specified as a parameter to the "new" method or via the "timezone" method.

During a time zone change such as +11 GMT to +10 GMT, there will be two possible UNIX times that can result in the same local time. In this case, like Time::Local::timelocal, this function will return the lower of the two times.

transition_times

This object method can be used to get the list of transition times for the current timezone. This method is only intended for testing the results of Time::Zone::Olson.

leap_seconds

This object method can be used to get the list of leap seconds for the current timezone. This method is only intended for testing the results of Time::Zone::Olson.

reset_cache

This object or class method can be used to reset the cache. This method is only intended for testing the results of Time::Zone::Olson. In actual use, cached values are only used if the mtime of the relevant files has not changed.

DIAGNOSTICS

%s is not a TZ file

The designated path did not have the TZif prefix at the start of the file. Maybe either the directory or the timezone name is incorrect?

Failed to read header from %s:%s

The designated file encountered an error reading either the V1 or V2 headers

Failed to read entire header from %s. %d bytes were read instead of the expected %d

The designated file is shorter than expected

%s is not an timezone in the existing Olson database

The designated timezone could not be found on the file system. The timezone is expected to be in the designated directory + the timezone name, for example, /usr/share/zoneinfo/Australia/Melbourne

%s does not have a valid format for a TZ timezone

The designated timezone name could not be matched by the regular expression for a timezone in Time::Zone::Olson

Failed to close %s:%s

There has been a file system error while reading or closing the designated path

Failed to open %s for reading:%s

There has been a file system error while opening the the designated path. This could be permissions related, or the timezone in question doesn't exist?

Failed to stat %s:%s

There has been a file system error while doing a stat on the designated path. This could be permissions related, or the timezone in question doesn't exist?

Failed to read %s from %s:%s

There has been a file system error while reading from the designated path. The file could be corrupt?

Failed to read all the %s from %s. %d bytes were read instead of the expected %d

The designated file is shorter than expected. The file could be corrupt?

The tz defintion at the end of %s could not be read in %d bytes

The designated file is longer than expected. Maybe the timezone version is greater than the currently recognized 3?

Failed to read tz definition from %s:%

There has been a file system error while reading from the designated path. The file could be corrupt?

Failed to parse the tz defintion of %s from %s

This is probably a bug in Time::Zone::Olson in failing to parse the TZ variable at the end of the file.

CONFIGURATION AND ENVIRONMENT

Time::Zone::Olson requires no configuration files or environment variables. However, it will use the values of $ENV{TZ} and $ENV{TZDIR} as defaults for missing parameters.

DEPENDENCIES

Time::Zone::Olson requires Perl 5.10 or better. For environments where the unpack 'q' parameter is not supported, the following module is also required

INCOMPATIBILITIES

None reported

BUGS AND LIMITATIONS

Please report any bugs or feature requests to bug-time-zone-olson at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Time-Zone-Olson. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SEE ALSO

AUTHOR

David Dick, <ddick at cpan.org>

LICENSE AND COPYRIGHT

Copyright 2015 David Dick.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.