You can have more than one calendar. Create one for work and another for your free time.
Select Calendar.
Select
> Calendars >
.
Enter a name, and set a color code for the calendar.
Define the visibility for the calendar. When a calendar is hidden, the calendar events and reminders are not displayed in different calendar views or on the home screen.
Select
.
In the Calendars view, select the desired calendar.
Change the name, color, and visibility.
Select
.
When adding a calendar event, select
and the calendar.
Fill in the fields, and select
.
Color codes indicate which calendar an event belongs to.