The present invention describes a solar powered garden lamp (100,100a,100b). The lamp (100,100a,100b) includes a lamp assembly, a solar panel (192), a rechargeable battery (150), a sunlight-hour switch (154), an LED (146a,146b) and a control circuit (140). In use, a user estimates the number of hours of sunlight incident on the solar panel (192) and the sunlight-hour switch (154) is calibrated by applying a weather variability factor on a battery charger (142) capacity that is connected to the solar panel. The solar panel (192) converts solar energy into electric power to recharge the battery (150) during the day so that the battery (150) has sufficient power to light up the LED (146a or 146b) at a predetermined brightness continuously from dusk to dawn.