diff --git a/Bin2Root2.cpp b/Bin2Root2.cpp
index 1e8dcbc..44c00e8 100644
--- a/Bin2Root2.cpp
+++ b/Bin2Root2.cpp
@@ -45,6 +45,14 @@ inline unsigned int getTime_us(){
 #include <filesystem>
 #include <regex>
 
+//^================================================
+///============ time offset
+std::vector<int64_t> timeOffsetList =  {0, 0, 0, 0};
+
+int bufferSize = 5000000;
+
+//^================================================
+
 std::vector<std::pair<int, std::string>> findDataFiles(const std::string& patternPrefix) {
   std::vector<std::pair<int, std::string>> results;
   std::regex pattern1(patternPrefix + "_" + R"_((\d{1,3})\.BIN)_");
@@ -86,7 +94,8 @@ int ReadBatch(int bufferSize){
       if( reader->ReadBlock() != 1 ){
         break;
       }
-      //<<< should apply time offset here
+      int bd = reader->data.BoardID;
+      if( bd < timeOffsetList.size() ) reader->data.TimeStamp += timeOffsetList[bd];
       hitList_A.push_back(reader->data);
     }
     if( hitList_A.size() >  1){
@@ -105,7 +114,8 @@ int ReadBatch(int bufferSize){
     if( reader->ReadBlock() != 1 ){
       break;
     }
-    //<<< should apply time offset here
+    int bd = reader->data.BoardID;
+    if( bd < timeOffsetList.size() ) reader->data.TimeStamp += timeOffsetList[bd];
     hitList_B.push_back(reader->data);
   }
   if( hitList_B.size() > 1 ){
@@ -194,15 +204,10 @@ int main(int argc, char **argv) {
 
   unsigned int runStartTime = getTime_us();
 
-  int bufferSize = 5000000;
-
   ///============= read input
   long timeWindow = atoi(argv[1]); // ns
   short runNum = atoi(argv[2]);
 
-  ///============ time offset
-  std::vector<int64_t> timeOffsetList =  {0, 0, 0, 0};
-
   ///=========== Form outFileName;
   TString outFileName = Form("run%03d_%s.root", runNum, (timeWindow < 0 ? "single" : std::to_string(timeWindow).c_str()) );