time: clarify platform specific timer resolution
@@ -72,7 +72,9 @@ pub fn sleep_until(deadline: Instant) -> Sleep {
///
/// No work is performed while awaiting on the sleep future to complete. `Sleep`
/// operates at millisecond granularity and should not be used for tasks that
-/// require high-resolution timers.
+/// require high-resolution timers. The implementation is platform specific,
+/// and some platforms (specifically Windows) will provide timers with a
+/// larger resolution than 1 ms.
///
/// To run something regularly on a schedule, see [`interval`].
///
