The answer to this question depends on factors such as the power and luminous efficiency of the luminaire used and the actual capacity and operating voltage of the battery. Generally speaking, an average power of 3W, high luminous efficiency incandescent bulb, need to consume about 0.25A of current, then a 10000mAh lithium battery in 100% charging state, can supply about 40 hours. If the LED bulb is used, the current consumption is about 0.05A, then the same battery can be powered for about 200 hours at 100% charge. Therefore, the specific number of clocks that can be illuminated needs to be calculated in combination with actual use.
Based on the information provided, we cannot accurately answer how long the bulb can be lit, because the power and use of the bulb will affect the battery life. If we know the power of the bulb, we can estimate the lighting time by dividing the battery capacity (12,000 mah) by the power of the bulb. However, please note that this is only an estimate and the actual use time may be affected by other factors, such as the health of the battery and the temperature of the environment in which it is used.