NAME¶

Date::Manip::TZdata -- Internal module for working with the tzdata files

SYNOPSIS¶

   use Date::Manip::TZdata;
   $tzd  = new Date::Manip::TZdata($dir);

DESCRIPTION¶

This module is not intended for public use. It is used internally by the scripts used to analyze the time zone database and generate the modules for each time zone. The module is included in the distribution solely for the sake of completeness. Currently, no support is offered for this module, and it can (and may) change without notice.

This module consists of routines for working with the tzdata files obtained from ftp://elsie.nci.nih.gov/pub/ . These files are updated several times a year and are the basis for time zone descriptions for most computer systems.

At some point, I am interested in making this module a direct interface to the tzdata files, but in the limited amount of time I have to work on perl modules, other modifications to Date::Manip are much higher priority, so I'm not sure when (or if) this will ever happen.

ROUTINES¶

new

   use Date::Manip::TZdata;
   $tzd  = new Date::Manip::TZdata($dir);
    

This finds and reads in all the tzdata. If $dir is passed in, it is the directory where a tzdata directory is located. It defaults to the current directory.

KNOWN LIMITATIONS¶

Some assumptions and limitations are assumed in the logic of this module.

When a time change occurs, the time may change backwards or forwards. Time changes rules are listed on a per-year basis. It is assumed that time changes will not occur so close to the end or start of the year as to cross the year boundary (in other words, the year will not change as a result of the time change). This is not accounted for, and it is hoped that this situation will never occur.

Also, because this module is strictly limited to 4 digit positive years (regardless of whether it is wallclock or universal time), and because various parts of the module switch back and forth, valid times for this module are from Jan 2, 0001 to Dec 30, 9999. This ensures that conversions from wallclock to universal or vice versa will never make dates occur in the year 0000 or 10000.

KNOWN BUGS¶

None known.

BUGS AND QUESTIONS¶

Please refer to the Date::Manip man page for information on submitting bug reports or questions to the author.

AUTHOR¶

Sullivan Beck (sbeck@cpan.org)