You can add in multiple Leave types each with different settings.

You will need a main "Leave/Holiday" type for general Annual Leave/Holiday.

[Leave Type - Name] The name that appears for all users.

[Leave Type - Status] You can disable or enable without deleting the type.

[Leave Type - Set globally] If set to "Yes" you can set a number of days for all employees i.e. 20 days per year.

[Leave Type - Number of days] Set the number of days for all employees if "Set globally" is "Yes" otherwise tick "unlimited" if dynamic i.e. "Sick" would be classed as dynamic. Where "Set globally" is "No" and "unlimited" is unticked you can set a number of days by the employee in there profile under the "Leave" Tab. See screenshot below for Setting individual employee leave.

[Leave Type - Deduct from allowance] Set to "Yes" to automatically deduct the number of days from employees allowance. You might set Annual leave to "yes" but "sick leave" to "no" for example.

[Leave Type - Applicable days] You can set what days this leave type will apply to. If you set Monday to Friday then employees will only be able to book leave on those days.

[Leave Type - Allow half days] If set to to "Yes" employees will get the option to book half day am or pm on leave booking.

[Leave Type - Allow during probation] You may wish to prevent leave for an employee that is still in probationary.

[Leave Type - Applies to gender] You can set some leave to certain leave type to different genders.

[Leave Type - Unused leave] You can set this to laps or carry forward at the end of your holiday calendar year. You can set holiday year start month in Settings > Calendar settings