The millisecond conversion selector above selects the time measurement unit to convert to starting from milliseconds (ms). To make a conversion starting from a unit of time other than millisecond, simply click on the "Reset" button.
The millisecond is a unit of time in the metric system equal to one thousandth of a second (1 ms = 10-3 s).
One millisecond (ms) is also equal to 1012 femtoseconds (fs), or 109 picoseconds (ps), or 106 nanoseconds (ns) or 103 microseconds (μs), which are SI units of time.
Times of this magnitude (i.e., on the millisecond time scale) are used in electronics.