Bug 16376 - Koha::Calendar->is_holiday date truncation creates fatal errors for TZ...

Bug 16376 - Koha::Calendar->is_holiday date truncation creates fatal errors for TZ America/Santiago

Using a DateTime object with a timezone of America/Santiago
was causing fatal errors for Koha::Calendar->is_holiday
and Koha::Calendar->exception_holidays, when the objects
were truncated to an invalid local time.

Using a floating zone allows us to use the same day, month, year
for comparison purposes without running into the possibility of
creating an invalid local time and thus a fatal software error.

Edit:

While the changes to is_holiday and single_holiday make sense (Jonathan agrees too)
I didn't manage to have them fail, because truncate is not failing in my trials, but
days_between. So to me, it narrows down to have exception_holiday return floating tz
datetime objects so it doesn't break days_between.

Anyway, it is ok to push this patch, and the regression test I provide covers this scenario
I'm describing.

To test:
- Apply the regression tests patch
- Run:
  $ prove t/db_dependent/Holidays.t
=> FAIL: Unexpected error due to bad timezone/date combination
- Apply this patch
- Run:
  $ prove t/db_dependent/Holidays.t
=> SUCCESS: Tests pass

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>