@paridata There is a module integrated into Odoo Community Edition and also Flectra, which handles vacations. It is/was called "Leaves" or "Time Off". The name changes with editions.
Both these applications are still waiting in the "App Wish List".
https://forum.cloudron.io/topic/1256/odoo-distributed-business-apps
https://forum.cloudron.io/topic/1403/flectra-erp-and-cms-an-open-source-alternative-do-odoo
https://www.odoo.com/app/time-off-features
