module Clock_ns : sig ... endmodule Time_ns : sig ... endmodule Time : sig ... endmodule Async_kernel_scheduler : sig ... endmodule Date : sig ... endval at : Time_ns.t -> unit Deferred.tval after : Time_ns.Span.t -> unit Deferred.tval every : ?start:unit Deferred.t -> ?stop:unit Deferred.t -> ?continue_on_error:bool -> Time_ns.Span.t -> (unit -> unit) -> unitval with_timeout : Time_ns.Span.t -> 'a Deferred.t -> [ `Timeout | `Result of 'a ] Deferred.t