NAME

       Test::MockTime - Replaces actual time with simulated time

SYNOPSIS

         use Test::MockTime qw( :all );
         set_relative_time(-600);

         # do some tests depending on time increasing from 600 seconds ago

         set_absolute_time(0);

         # do some more tests depending on time starting from the epoch
         # epoch may vary according to platform.  see perlport.

         set_fixed_time(CORE::time());

         # do some more tests depending on time staying at the current actual time

         set_absolute_time('1970-01-01T00:00:00Z');

         # do some tests depending on time starting at Unix epoch time

         set_fixed_time('01/01/1970 00:00:00', '%m/%d/%Y %H:%M:%S');

         # do some tests depending on time staying at the Unix epoch time

         restore_time();

         # resume normal service

DESCRIPTION

       This module was created to enable test suites to test code at specific points in time.
       Specifically it overrides localtime, gmtime and time at compile time and then relies on
       the user supplying a mock time via set_relative_time, set_absolute_time or set_fixed_time
       to alter future calls to gmtime,time or localtime.

Functions

       set_absolute_time
           If given a single, numeric argument, the argument is an absolute time (for example, if
           0 is supplied, the absolute time will be the epoch), and calculates the offset to
           allow subsequent calls to time, gmtime and localtime to reflect this.

           for example, in the following code

             Time::Mock::set_absolute_time(0);
             my ($start) = time;
             sleep 2;
             my ($end) = time;

           The $end variable should contain 2 seconds past the epoch;

           If given two arguments, the first argument is taken to be an absolute time in some
           string format (for example, "01/01/1970 00:00:00").  The second argument is taken to
           be a "strptime" format string (for example, "%m/%d/%Y %H:%M:%S").  If a single
           argument is given, but that argument is not numeric, a "strptime" format string of
           "%Y-%m-%dT%H:%M:%SZ" is assumed.

           for example, in the following code

             Time::Mock::set_absolute_time('1970-01-01T00:00:00Z');
             my ($start) = time;
             sleep 2;
             my ($end) = time;

           The $end variable should contain 2 seconds past the Unix epoch;

       set_relative_time($relative)
           takes as an argument an relative value from current time (for example, if -10 is
           supplied, current time be converted to actual machine time - 10 seconds) and
           calculates the offset to allow subsequent calls to time,gmtime and localtime to
           reflect this.

           for example, in the following code

             my ($start) = time;
             Time::Mock::set_relative_time(-600);
             sleep 600;
             my ($end) = time;

           The $end variable should contain either the same or very similar values to the $start
           variable.

       set_fixed_time
           If given a single, numeric argument, the argument is an absolute time (for example, if
           0 is supplied, the absolute time will be the epoch).  All subsequent calls to gmtime,
           localtime and time will return this value.

           for example, in the following code

             Time::Mock::set_fixed_time(time)
             my ($start) = time;
             sleep 3;
             my ($end) = time;

           the $end variable and the $start variable will contain the same results

           If given two arguments, the first argument is taken to be an absolute time in some
           string format (for example, "01/01/1970 00:00:00").  The second argument is taken to
           be a "strptime" format string (for example, "%m/%d/%Y %H:%M:%S").  If a single
           argument is given, but that argument is not numeric, a "strptime" format string of
           "%Y-%m-%dT%H:%M:%SZ" is assumed.

       restore()
           restore the default time handling values.  "restore_time" is an alias. When exported
           with the 'all' tag, this subroutine is exported as "restore_time".

AUTHOR

       David Dick <ddick@cpan.org>

PREREQUISITES

       Time::Piece 1.08 or greater

BUGS

       Probably.

COPYRIGHT

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.

ACKNOWLEDGEMENTS

       Thanks to a use.perl.org journal entry <http://use.perl.org/~geoff/journal/20660> by
       Geoffrey Young.