It is generally recommended to inform your employer of your decision to resign as soon as possible. This shows professionalism and allows for a smoother transition for both parties. However, it is important to consider your individual circumstances and company culture when deciding on the timing of your resignation. It is advisable to have a conversation with your manager at a time when they are not too busy and when you have prepared yourself for the discussion. Ultimately, the most important thing is to communicate your decision respectfully and professionally.