My Calendar
Your personal calendar lets you keep track of your scheduled events such as meetings, business trips, vacations and other absences.
To view your calendar:
Open your profile and click Calendar on the sidebar:
View your schedule for a Day, 5 days, Week, or Month using the switch in the top right, or pick a specific date using the menu in the top left:
Add an event to your calendar
To create an absence, click 
in the top right, choose New absence and follow the instruction.
To create a meeting, either click and choose New meeting, or click the desired vacant day/time slot inside the calendar (in the Day, 5 Days, or Week view) then follow the instruction.
View another person's calendar
Whether you're scheduling a meeting or planning to collaborate with your teammates, you might want to check their calendars to ensure availablity.
Open the person's profile (press Ctrl+K to find it).
Click Calendar of.. under the Meetings widget.
To schedule a meeting with the calendar owner, find and click the most suitable time slot in their calendar, then follow the instruction.