4 ms·

I’m personally partial to attolightyears (about 1cm).

• Chris2048 2y ago
  Surely you'd use the base unit of time, the second (lightseconds)? atto-lightyear = 1e-18 lightyear lightyear = 3.156e+7 lightsecond Hence, atto-lightyear = 3.156e-11 lightsecond = 31.56 pico-lightsecond