The general rule of thumb is 3 months. Ensure that your food has completely cooled to room temperature before you place the lid on or seal the bag up. Once cooled and sealed, place in the freezer for up to 3 months. I defrost my meals in the fridge overnight, or you could get them out in the morning and leave in a shady spot in the kitchen to defrost (a good place to leave it for the day is the microwave!). Reheat as required.