Yes - all workers are entitled to paid holiday which begins to accrue as soon as they start their job. This includes casual workers who may work one day a week or sporadically as needed.
Irregular workers will have their paid leave calculated on the number of hours they have worked during the leave year or will receive one week’s paid holiday based on the average weekly pay they received during the previous 12 weeks. Hourly paid irregular workers must not have their holiday pay included in their hourly pay rate.
How much paid holiday they are entitled to depends on the amount they have accrued within your standard company leave year. All workers are entitled to 28 days holiday per year and this is calculated pro-rata for a part-time worker. A worker’s entitlement is calculated based on their start date within the company’s leave year.
Your company policy will determine whether an employee can take their holiday entitlement in advance or whether they need to have worked for enough time to have accrued the amount of holiday they want to take.