A leave policy that gets argued about every month is not a policy. Here is the structure that stops the argument.
Attendance is the most disputed area in almost every business we audit, and the reason is nearly always the same: the policy states the entitlement but not the mechanism.
Entitlement is the easy half
Twelve casual leaves, twelve sick leaves, some earned leave. Every policy gets this part right. Then the arguments start over everything the document did not say.
The half most policies skip
Who approves, and within how long? What happens when someone applies after the fact? Is half-day defined by hours or by session? What is the grace period for late arrival, and how many are allowed before it becomes an absence? Does unapproved leave become loss of pay automatically, or does someone decide? What happens to unused leave at year end — lapse, carry forward, or encashment, and up to what limit?
Write the mechanism
Every one of those questions needs a written answer, applied the same way for everyone. That is the whole trick. A policy is not a statement of entitlement, it is a set of decisions made in advance so that no one has to make them under pressure.
One more thing: whatever you write, make sure your attendance system can actually produce the data to enforce it. A policy your records cannot support is a policy you will lose.