Test::MockTime::DateCalc -- fake time for Date::Calc functions

       Copyright 2009, 2010, 2011, 2019 Kevin Ryde

       Test-MockTime-DateCalc is free software; you can redistribute it and/or modify it under the terms of the
       GNU General Public License as published by the Free Software Foundation; either version 3, or (at your
       option) any later version.

       Test-MockTime-DateCalc is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       General Public License for more details.

       You should have received a copy of the GNU General Public License along with Test-MockTime-DateCalc.  If
       not, see <http://www.gnu.org/licenses/>.

perl v5.36.0                                       2022-10-16                      Test::MockTime::DateCalc(3pm)

       "Test::MockTime::DateCalc" arranges for the functions in "Date::Calc" to follow the Perl level "time()"
       function (see perlfunc) and in particular any fake date/time set there by "Test::MockTime".  The
       following "Date::Calc" functions are changed

           System_Clock
           Today
           Now
           Today_and_Now
           This_Year

           Gmtime
           Localtime
           Timezone
           Time_to_Date

       "Gmtime", "Localtime", "Timezone" and "Time_to_Date" are made to default to the Perl-level current
       "time()".  When called with an explicit time argument, they're unchanged.

   ModuleLoadOrder
       "Test::MockTime" or similar fakery must be loaded first, before anything with a "time()" call, which
       includes "Test::MockTime::DateCalc".  This is the same as for any "CORE::GLOBAL" override, see
       "OVERRIDING CORE FUNCTIONS" in CORE.

       "Test::MockTime::DateCalc" must be loaded before "Date::Calc".  If "Date::Calc" is already loaded then
       its functions might have been imported into other modules and such imports are not affected by the
       redefinitions made.  For that reason, "Test::MockTime::DateCalc" demands it be the one to load
       "Date::Calc" for the first time.  Usually this simply means having "Test::MockTime::DateCalc" at the
       start of a test script, before the things you're going to test.

           use strict;
           use warnings;
           use Test::MockTime ':all';
           use Test::MockTime::DateCalc;

           use My::Foo::Bar;

           set_fixed_time('1981-01-01T00:00:00Z');
           is (My::Foo::Bar::something(), 1981);
           restore_time();

       In a test script, it's often good to have your own modules early to check they correctly load their pre-
       requisites.  You might want a separate test script for that so as not to accidentally rely on
       "Test::MockTime::DateCalc" loading "Date::Calc".

   OtherFakingModules
       "Test::MockTime::DateCalc" can be used with other modules which mangle the Perl-level "time" too.  For
       example "Time::Fake",

           use Time::Fake;                # fakery first
           use Test::MockTime::DateCalc;

       Or "Time::Mock",

           use Time::Mock;                # fakery first
           use Test::MockTime::DateCalc;

       "Time::Warp" (as of version 0.5) only exports a new "time", it's not a core override and so can't be used
       with "Test::MockTime::DateCalc".

http://user42.tuxfamily.org/test-mocktime-datecalc/index.html

       Test::MockTime::DateCalc -- fake time for Date::Calc functions

       Date::Calc, Test::MockTime, Time::Fake, Time::Mock

       faketime(1)

        use Test::MockTime;
        use Test::MockTime::DateCalc; # before Date::Calc loads
        # ...
        use My::Module::Using::Date::Calc;