Timescale (noun)

1. A system of measuring time, especially a system that divides time into units of measurement such as days, weeks, months, and years.
2. A period of time during which a particular event or process takes place or is expected to take place.

Origin:

Mid 19th century: from time + scale.

Examples:

1. The timescale for completing the project is one year.
2. The timescale for the geologic history of the earth is divided into eras, periods, and epochs.
3. The timescale for human evolution is measured in millions of years.
4. The timescale for the solar system's formation is estimated to be around 4.6 billion years ago.
5. The timescale for the construction of the Great Pyramid of Giza is estimated to be 20 years.