The kilosecond (ks) is a unit of time in the International System of Units, defined as 103 seconds using the SI prefix system. SI units of time longer than a second, including kiloseconds, are rarely used because the traditional units of time, such as minutes, hours, and days are still widely used worldwide. Kilosecond is most commonly mentioned in the field of astrophysics. One kilosecond is 16.6 minutes and there are 86.4 kiloseconds in a 24 hour day.