When the admin user logs in for the first time, their timezone can be updated based on the cookies of their browser. In such case, the timezone of the default working calendar should be updated too. Related: https://github.com/odoo/odoo/pull/83262/ Task 2759592 closes odoo/odoo#87061 X-original-commit: 3c56be1732d219ed69efe5f18bd7931959b7c333 Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>