diff --git a/DAQ/src/EventHeaderFromCFOFragment_module.cc b/DAQ/src/EventHeaderFromCFOFragment_module.cc
index 063582efed..abde98f418 100644
--- a/DAQ/src/EventHeaderFromCFOFragment_module.cc
+++ b/DAQ/src/EventHeaderFromCFOFragment_module.cc
@@ -4,30 +4,36 @@
 //
 // ======================================================================
 
+// Framework
 #include "art/Framework/Core/EDProducer.h"
 #include "art/Framework/Principal/Event.h"
 #include "art/Framework/Services/Registry/ServiceHandle.h"
 #include "fhiclcpp/ParameterSet.h"
-
 #include "art/Framework/Principal/Handle.h"
+
+// artdaq
 #include <artdaq-core-mu2e/Data/EventHeader.hh>
 #include "artdaq-core-mu2e/Overlays/CFOEventFragment.hh"
+#include "artdaq-core-mu2e/Overlays/CFO_Packets/CFO_Event.h"
+#include "artdaq-core-mu2e/Overlays/CFO_Packets/CFO_EventRecord.h"
 #include "artdaq-core-mu2e/Overlays/FragmentType.hh"
-
 #include <artdaq-core/Data/Fragment.hh>
 
-#include <iostream>
+// Offline
+#include "Offline/DataProducts/inc/EventWindowMarker.hh"
 
+// C++
+#include <iostream>
 #include <string>
-
 #include <array>
 #include <list>
 #include <memory>
 #include <unordered_map>
 #include <vector>
 
+// TRACE
 #include "trace.h"
-#define TRACE_NAME "Mu2eSubEventReceiver"
+#define TRACE_NAME "EventHeaderFromCFOFragment"
 
 namespace art {
 class EventHeaderFromCFOFragment;
@@ -39,8 +45,11 @@ class art::EventHeaderFromCFOFragment : public EDProducer {
 
 public:
   struct Config {
-    fhicl::Atom<art::InputTag> cfoTag   {fhicl::Name("cfoTag"),    fhicl::Comment("Input module")};
-    fhicl::Atom<int>           diagLevel{fhicl::Name("diagLevel"), fhicl::Comment("diagnostic level")};
+    using Name    = fhicl::Name;
+    using Comment = fhicl::Comment;
+    fhicl::Atom<art::InputTag> cfoTag   {Name("cfoTag"),    Comment("Input CFO fragment tag")};
+    fhicl::Atom<bool>          ewm      {Name("createEWM"), Comment("Produce an event window marker object")};
+    fhicl::Atom<int>           diagLevel{Name("diagLevel"), Comment("diagnostic level")};
   };
 
   // --- C'tor/d'tor:
@@ -54,6 +63,7 @@ class art::EventHeaderFromCFOFragment : public EDProducer {
 
 private:
   art::InputTag cfoFragmentTag_;
+  bool          ewm_;
   int           diagLevel_;
 };
 
@@ -65,8 +75,13 @@ art::EventHeaderFromCFOFragment::EventHeaderFromCFOFragment(
     const art::EDProducer::Table<Config>& config) :
     art::EDProducer{config},
     cfoFragmentTag_(config().cfoTag()),
+    ewm_(config().ewm()),
     diagLevel_(config().diagLevel()) {
   produces<mu2e::EventHeader>();
+  if(ewm_) {
+    TLOG(TLVL_DEBUG + 2) << "Producing EventWindowMarker";
+    produces<mu2e::EventWindowMarker>();
+  }
 }
 
 // ----------------------------------------------------------------------
@@ -74,30 +89,41 @@ art::EventHeaderFromCFOFragment::EventHeaderFromCFOFragment(
 void art::EventHeaderFromCFOFragment::produce(Event& event) {
 
   // Collection of CaloHits for the event
-  std::unique_ptr<mu2e::EventHeader> evtHdr(new mu2e::EventHeader);
-  art::Handle<artdaq::Fragments>     cfoFragmentHandle;
+  std::unique_ptr<mu2e::EventHeader>       evtHdr(new mu2e::EventHeader);
+  std::unique_ptr<mu2e::EventWindowMarker> ewm((ewm_) ? new mu2e::EventWindowMarker : nullptr);
+  art::Handle<artdaq::Fragments>           cfoFragmentHandle;
 
   if(!event.getByLabel(cfoFragmentTag_, cfoFragmentHandle)) {
     event.put(std::move(evtHdr));
-    TLOG(TLVL_DEBUG) << "No CFO fragments found";
+    if(ewm_) event.put(std::move(ewm));
+    TLOG(TLVL_DEBUG + 1) << "No CFO fragments found";
     return;
   }
 
   const auto *fragments = cfoFragmentHandle.product();
   if (fragments->size()>0){
     const auto &frag = fragments->at(0);
-    mu2e::CFOEventFragment   cfoFrag(frag);
-    const CFOLib::CFO_Event  cfo = cfoFrag.getData();
-    //const CFO_EventRecord&   cfoRecord = cfo.GetEventRecord();
-    evtHdr->mode  = 0;//cfo.GetEventMode();
-    evtHdr->ewt   = static_cast<long unsigned int>(cfo.GetEventWindowTag().GetEventWindowTag().to_ullong());
-    evtHdr->flags = cfo.GetEventMode().isOnSpillFlagSet();
-    TLOG(TLVL_DEBUG+20) << "mode = "<< evtHdr->mode <<" ewt  = "<< evtHdr->ewt << " flags = " << evtHdr->flags;
-  }else {
-    TLOG(TLVL_DEBUG) << "No CFO fragments found in the event";
+    const mu2e::CFOEventFragment   cfoFrag(frag);
+    const CFOLib::CFO_Event        cfo       = cfoFrag.getData();
+    const CFOLib::CFO_EventRecord& cfoRecord = cfo.GetEventRecord();
+    evtHdr->mode          = 0;//cfo.GetEventMode();
+    evtHdr->ewt           = static_cast<long unsigned int>(cfo.GetEventWindowTag().GetEventWindowTag().to_ullong());
+    evtHdr->flags         = cfo.GetEventMode().isOnSpillFlagSet();
+    evtHdr->eventDuration = cfoRecord.event_duration;
+    TLOG(TLVL_DEBUG + 20) << "mode = " << evtHdr->mode << " ewt  = "<< evtHdr->ewt << " flags = " << evtHdr->flags
+                          << " onspill = " << evtHdr->isOnSpill() << " duration = " << evtHdr->eventDuration;
+  } else {
+    TLOG(TLVL_DEBUG + 3) << "No CFO fragments found in the event";
+  }
+
+  if(ewm_) {
+    constexpr double tick = 25.; // clock ticks -> ns
+    ewm->_spillType   = (evtHdr->isOnSpill()) ? mu2e::EventWindowMarker::SpillType::onspill : mu2e::EventWindowMarker::SpillType::offspill;
+    ewm->_eventLength = tick * evtHdr->eventDuration;
   }
 
   event.put(std::move(evtHdr));
+  if(ewm_) event.put(std::move(ewm));
 } // produce()
 
 // ======================================================================