Bug 23382: (RM follow-up) Days of the week discrepancies

Bug 23382: (RM follow-up) Days of the week discrepancies

DateTime and C4::Calander have different notions of 'days of the week'.

DateTime days go from 1..7 (Mon..Sun) whilst C4::Calendar expects 0..6
(Sun..Sat).  This patch adapts the holday setting in the tests to ensure
we work when testing Saturdays and Sundays.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 1823316503331bcfffbf1e96528f53b66a8893b7)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>