SAT is an internationally recognised standardised test that evaluates your knowledge in reading, writing and quantitative aptitude and other specialised subjects. It is taken for undergraduate admission in United states and some other countries. SAT test pattern has four sections- Evidence-Based Reading and Writing, Reading Test, Writing and Language Test and Math while the Essay is optional. It is offered seven times each year in the US and six times internationally. You can sit for SAT test in October, November, December, January, March, May and June. To check complete information about you can go through with given below link.

SAT

Good Luck! 

SAT exam evaluates students knowledge on the basis of reading, writing and quantitative aptitude and other specialised subjects.

It is taken for undergraduate admission in the United States and some other countries.

As such there is no eligibility criteria and age limit in this exam but students are advised to take the test when they are in senior high school.

To check in detail about the exam you can refer below link

SAT Test

Good Luck!!