Can I take a half day?
Half days depend on whether a leave quota is configured to hold fractions, and on what the employer's policy allows. Where both permit it, a half day draws half a day from an allowance rather than a whole one. Which half is taken matters as much as the fact of it.
Granularity is the entire value of the arrangement. An appointment at three in the afternoon does not need a whole day of somebody's annual allowance.
A system dealing only in whole days forces exactly that waste, and people respond by taking the whole day because they have already paid for it.
Which half is taken is the operational half of the question. Two people off on the same morning is a very different cover problem from two people taking opposite halves.
So the request needs to say which one, and the planning view needs to show it.
Whether fractions are possible at all comes down to configuration. Where a quota holds whole days only, teams round, and it matters which way they round before anybody relies on it.
Notice is the other variable. Many teams allow a shorter run-up for half days, on the reasonable grounds that half a day disturbs cover less than a whole one. That is a policy choice rather than a product rule.
Check both before the request goes in. Two short checks now beat one awkward conversation later.
Two half days in one week catch people out. Some policies treat them as one day off a balance and nothing more. Others count each as a separate occasion, which matters where short absences are limited.
Check how your quota is configured before relying on fractions. Where it holds whole days only, teams round, and it is worth knowing which way before the request goes in.
Related questions
Is a half day the same as a partial day?
No. A half day is planned and approved and touches a balance. A partial day is what the attendance record observed, arranged or not.
Does a half day need the same notice?
That is your policy's decision. Many teams allow shorter notice for half days, since they disrupt cover less than a full day does.
How does it show in planning?
The capacity grid marks leave against the days it covers. How a fractional day appears depends on how the allocation is configured.