Time_utils.TimestampTimestamp creation and manipulation
val now : unit -> timestamp_nsval now_monotonic : unit -> timestamp_nsval of_unix_time_s : float -> timestamp_nsval to_unix_time_s : timestamp_ns -> floatval of_unix_time_ms : int64 -> timestamp_nsval to_unix_time_ms : timestamp_ns -> int64val of_unix_time_us : int64 -> timestamp_nsval to_unix_time_us : timestamp_ns -> int64val add_duration : timestamp_ns -> duration_ns -> timestamp_nsval sub_duration : timestamp_ns -> duration_ns -> timestamp_nsval diff : timestamp_ns -> timestamp_ns -> duration_nsval compare : timestamp_ns -> timestamp_ns -> intval to_string : timestamp_ns -> string