How effective the sunscreen you have chosen ?
Even if it seems to you that you are not exposed to sunlight, this is not entirely. They tend to penetrate through clothes, umbrellas, even through the windows of the room. Try to regularly test your skin for mini-ozhins and stains. If despite the fact that you use the cream, new burns and spots appear on your skin, without hesitation, change the old cream to another that will provide you with better protection.
Most sunscreen states that they have an expiration date of up to three years. This is a rather solid period and funds can really be consumed all this time, but their properties are changing. It is generally accepted that the printed cream can be used for no more than one year since its opening.