diff --git a/crates/items_2/src/binning/container_events.rs b/crates/items_2/src/binning/container_events.rs
index f45a32c..d2378f1 100644
--- a/crates/items_2/src/binning/container_events.rs
+++ b/crates/items_2/src/binning/container_events.rs
@@ -48,6 +48,7 @@ impl EventValueType for f32 {
     type AggregatorTimeWeight = AggregatorNumeric<Self>;
 }
 
+#[derive(Debug, Clone)]
 pub struct EventSingle<EVT> {
     pub ts: TsNano,
     pub val: EVT,
@@ -102,6 +103,12 @@ where
         self.tss.back().map(|&x| x)
     }
 
+    pub fn len_before(&self, end: TsNano) -> usize {
+        let pp = self.tss.partition_point(|&x| x < end);
+        assert!(pp <= self.len(), "len_before  pp {}  len {}", pp, self.len());
+        pp
+    }
+
     pub fn event_next(&mut self) -> Option<EventSingle<EVT>> {
         if let (Some(ts), Some(val)) = (self.tss.pop_front(), self.vals.pop_front()) {
             Some(EventSingle { ts, val })
diff --git a/crates/items_2/src/binning/timeweight/timeweight_events.rs b/crates/items_2/src/binning/timeweight/timeweight_events.rs
index b5d700b..7612d63 100644
--- a/crates/items_2/src/binning/timeweight/timeweight_events.rs
+++ b/crates/items_2/src/binning/timeweight/timeweight_events.rs
@@ -24,8 +24,11 @@ pub enum Error {
     AnotherBeforeRange,
     NoLstAfterFirst,
     EmptyContainerInnerHandler,
+    NoLstButMinMax,
 }
 
+type MinMax<EVT> = (EventSingle<EVT>, EventSingle<EVT>);
+
 struct InnerA<EVT> {
     range: BinnedRange<TsNano>,
     cnt: u64,
@@ -91,9 +94,17 @@ where
                 // Do I maybe need both?
                 // How to handle to not emit bins until at least some partially filled bin is encountered?
                 // How to implement the bin cycle logic in clean way?
+                // How to emit things? Do to ship results to the caller?
                 todo!("must check if ev is already after range.");
             }
 
+            if ev.ts >= self.range.nano_end() {
+                todo!("make sure that the transition to the next bin (if we want any next bin) works");
+                todo!("keep lst. we derive min/max from lst upon the first event in range");
+
+                // TODO where and how do I initialize min/max ?
+            }
+
             // TODO if the event is exactly on the current bin first edge, then there is no contribution to the avg yet
             // and I must initialize the min/max with the current event.
             // If the event is after the current bin first edge, then min/max is initialized from the lst
@@ -106,7 +117,33 @@ where
         Ok(())
     }
 
-    fn ingest_with_lst(&mut self, evs: ContainerEvents<EVT>, lst: &mut EventSingle<EVT>) -> Result<(), Error> {
+    fn ingest_with_lst_nominmax(
+        &mut self,
+        evs: ContainerEvents<EVT>,
+        lst: &mut EventSingle<EVT>,
+        minmax: &mut Option<MinMax<EVT>>,
+    ) -> Result<(), Error> {
+        // TODO how to handle the min max? I don't take event data yet out of the container.
+        todo!("minmax handle");
+        if let Some(ts0) = evs.ts_first() {
+            if ts0 < self.range.nano_beg() {
+                Err(Error::AnotherBeforeRange)
+            } else {
+                self.ingest_with_lst_ge_range_beg(evs, lst)
+            }
+        } else {
+            Err(Error::EmptyContainerInnerHandler)
+        }
+    }
+
+    fn ingest_with_lst_minmax(
+        &mut self,
+        evs: ContainerEvents<EVT>,
+        lst: &mut EventSingle<EVT>,
+        minmax: &mut MinMax<EVT>,
+    ) -> Result<(), Error> {
+        // TODO how to handle the min max? I don't take event data yet out of the container.
+        todo!("minmax handle");
         if let Some(ts0) = evs.ts_first() {
             if ts0 < self.range.nano_beg() {
                 Err(Error::AnotherBeforeRange)
@@ -125,6 +162,7 @@ where
 {
     inner_a: InnerA<EVT>,
     lst: Option<EventSingle<EVT>>,
+    minmax: Option<(EventSingle<EVT>, EventSingle<EVT>)>,
 }
 
 impl<EVT> BinnedEventsTimeweight<EVT>
@@ -139,12 +177,17 @@ where
                 _t1: PhantomData,
             },
             lst: None,
+            minmax: None,
         }
     }
 
     fn ingest_event_without_lst(&mut self, ev: EventSingle<EVT>) -> Result<(), Error> {
-        if ev.ts < self.inner_a.range.nano_end() {
-            if ev.ts >= self.inner_a.range.nano_beg() {
+        let range = &self.inner_a.range;
+        let beg = range.nano_beg();
+        let end = range.nano_end();
+        if ev.ts < end {
+            if ev.ts >= beg {
+                self.minmax = Some((ev.clone(), ev.clone()));
                 self.inner_a.cnt += 1;
             }
             self.lst = Some(ev);
@@ -157,7 +200,11 @@ where
             self.ingest_event_without_lst(ev)?;
         }
         if let Some(lst) = self.lst.as_mut() {
-            self.inner_a.ingest_with_lst(evs, lst)
+            if let Some(minmax) = self.minmax.as_mut() {
+                self.inner_a.ingest_with_lst_minmax(evs, lst, minmax)
+            } else {
+                self.inner_a.ingest_with_lst_nominmax(evs, lst, &mut self.minmax)
+            }
         } else {
             Err(Error::NoLstAfterFirst)
         }
@@ -167,9 +214,17 @@ where
     // and with respect to the last container, if any.
     fn ingest_ordered(&mut self, evs: ContainerEvents<EVT>) -> Result<(), Error> {
         if let Some(lst) = self.lst.as_mut() {
-            self.inner_a.ingest_with_lst(evs, lst)
+            if let Some(minmax) = self.minmax.as_mut() {
+                self.inner_a.ingest_with_lst_minmax(evs, lst, minmax)
+            } else {
+                self.inner_a.ingest_with_lst_nominmax(evs, lst, &mut self.minmax)
+            }
         } else {
-            self.ingest_without_lst(evs)
+            if self.minmax.is_some() {
+                Err(Error::NoLstButMinMax)
+            } else {
+                self.ingest_without_lst(evs)
+            }
         }
     }