Sunsets almost always occur towards the end of the day and give pensioners with bladder problems the opportunity to enjoy an ever changing vista of spectacular beauty without spending a penny.

Sunsets are caused by the diffraction of light through particulate suspensions in the atmosphere and are therefore most noticeable in the vicinity of coal-fired power stations, slaughterhouses and the homes of heavy smokers.

The best UK sunsets are seen from Hengistbury Head in Dorset, where the local SAS (Sunset Appreciation Society) has catalogued over 26,000 different forms of sunset, including 33 which included the colour green and 168 which included at least two cormorants.

Sunsets have inspired many visual artists, including Edward Munch, Vincent van Gogh and Jacques Tati, whose mime featured in Jean Luc Goddard’s remake of Sunset Boulevard.