The end datetime is not timezoned in _adjust_to_calendar before defining the search_range and using the _get_closest_work_time method.
Since _get_closest_work_time will timezone the timestamp received to start searching, the search interval needs to refer to the same end timestamp to avoid erratic behaviors.

Task-2628876

closes odoo/odoo#76374

Related: odoo/enterprise#20783
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>