Based on the information provided, you have worked for the company for 4 years and 1 month and plan to submit your resignation notice in January 2024, which is three months in advance according to the offer letter requirements. Regarding your annual leave calculation for the year 2024, it would depend on the company's policy and the applicable employment laws in your jurisdiction. Typically, annual leave entitlement is accrued on a pro-rata basis, which means that for every completed month of service, you earn a certain number of days of annual leave. To determine the exact calculation, you would need to refer to the company's leave policy or consult with your HR department. They will be able to provide you with the specific details on how your annual leave is accrued and if there are any restrictions on utilizing the entire leave balance during your notice period. It's essential to communicate your intentions regarding the utilization of your remaining annual leave in your resignation letter or when discussing your notice period with your employer to ensure clarity on both sides. Remember, each company may have different policies and regulations regarding annual leave, so it's crucial to consult with the appropriate HR personnel or refer to the company's policies for accurate information.