Preeti123, here is link to EXPL tutorial on creating schedules, https://experienceleague.adobe.com/docs/workfront-learn/tutorials-workfront/administration-and-setup... You can input holidays, half days, etc. within the schedule and assign it to the users that need it. The usual default set up in the Workfront system is to use the user's schedule, meaning the project timeline will respect the user's schedule they have set in their profile.
You can only have one schedule for a project, not multiples.