An egg timer is a device whose primary function is to measure a set amount of time. Its primary purpose was to assist in cooking an egg in water. Some later designs allowed adjustments to measure many other cookery tasks.

Technology
Traditionally these have been made as small hourglasses and the name has come to be synonymous with this form. Later mechanical countdown timers were introduced which had an adjustable dial and could be applied to a wide range of timed cooking tasks. Most recently digital timers have also  been manufactured and a wide selection of software is available to perform this task on a computer or mobile phone, and the task is simple to perform on most microwaves and oven timers.

The hourglass was invented at some time during the 14th century in medieval Europe. The first reliable pictorial representation dates from AD 1338, whilst

the earliest written records come from the same period and appear in lists of ships stores. From the 15th century onwards they were being used in a wide range of applications at sea, in the church , in industry and in cookery. They were the first dependable, reusable and reasonably accurate measure of time. The rate of flow of the sand is independent of the depth in the upper reservoir, and the instrument is not liable to freeze.

Egg boiling