Night or nighttime (also spelled night-time or night time) is the period of ambient darkness from sunset to sunrise during each 24-hour day, when the Sun is below the horizon. The exact time when night begins and ends (equally true with evening) depends on the location and varies throughout the year. When night is considered as a period that follows evening, it is usually considered to start around 8 pm and to last to about 4 am.

A sight is an aiming device used to assist in visually aligning ranged weapons, surveying instruments or optical illumination equipments with the intended target. Sights can be a simple set or system of markers that have to be aligned together with the target (such as iron sights on firearms), or optical devices that allow the user to see a sometimes optically enhanced (e.g. magnified) image of the target aligned in the same focus with an aiming point (e.g. telescopic sights, reflector sights and holographic sights). There are also sights that project an aiming point (or a "hot spot") onto the target itself, such as laser sights and infrared illuminators on some night vision devices.[citation needed].