This patch adds unit tests for the previous changes and centralize the
timezone handle into the Koha::DateUtils module.
Like that the behavior will affect all date manipulations using this
module (should be all dates in Koha).
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>