Quick answer
Use the + button to open the Add leave form, choose Who for, set the dates and send it. As an admin you can book for anyone, and the person is notified.
Find it under
Open the Add leave form
Click the + (Book time off) button in the top bar. Choose Who for and the leave Type.
Set the dates and send
Set Starting and Ending, add an optional reason, and choose Send request. Turn on Skip approval first if you want it approved straight away. Weekends and non-working days are not deducted.
Half days
For a single working day the form offers Full day, Morning ½ or Afternoon ½. For a longer range you can mark the first or last day as a half day.
Adding leave that already happened?
Pick the past dates and turn on Skip approval. See Enter past or historic leave.