diff --git a/pttodoest/src/main.rs b/pttodoest/src/main.rs
index aac166b..e8fc34b 100755
--- a/pttodoest/src/main.rs
+++ b/pttodoest/src/main.rs
@@ -9,6 +9,8 @@ fn main() {
 
     if !flags.dry_run {
         for file in files.files.iter() {
+            file.stage_new_persisted()
+                .expect("failed to stage new log files");
             file.persist_stage()
                 .expect("failed to persist staged changes to log file");
             file.stage_persisted().expect("failed to stage log files");
@@ -157,6 +159,25 @@ impl File {
         Events::new(&self.file)
     }
 
+    pub fn stage_new_persisted(&self) -> Result<(), String> {
+        let events = self.events()?;
+        let stage_mod_time = std::fs::metadata(&self.file)
+            .unwrap()
+            .modified()
+            .unwrap()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_secs();
+        let new_persisted: Vec<Delta> = events
+            .0
+            .iter()
+            .filter(|x| x.ts > stage_mod_time)
+            .map(|x| x.clone())
+            .collect();
+        panic!("not impl: apply filtered deltas to stage");
+        Ok(())
+    }
+
     pub fn stage_persisted(&self) -> Result<(), String> {
         let stage = self.events()?.snapshot()?;
         let plaintext = serde_yaml::to_string(&stage).unwrap();
@@ -368,6 +389,48 @@ mod test_file {
             tests::file_contains(&d, "plain", "- initial\n- 1");
         });
     }
+
+    #[test]
+    fn test_stage_new_persisted() {
+        tests::with_dir(|d| {
+            tests::write_file(&d, "plain", "- old\n- new");
+            tests::write_file(
+                &d,
+                ".plain.host",
+                format!(
+                    r#"
+                        {{"ts":{}, "patch":{{"op":"replace", "path":"/0", "value": "enqueued for persistence"}}}}
+                    "#,
+                    2147483647,
+                ).as_str(),
+            );
+
+            let f = File::new(&d.path().join("plain").to_str().unwrap().to_string());
+
+            assert_eq!(1, f.events().unwrap().0.len());
+            assert_eq!(2, f.stage().unwrap().len());
+            tests::file_contains(&d, "plain", "old");
+            tests::file_contains(&d, "plain", "new");
+
+            f.stage_new_persisted().unwrap();
+            tests::file_contains(&d, "plain", "enqueued");
+            tests::file_contains(&d, "plain", "new");
+            assert_eq!(1, f.events().unwrap().0.len());
+            assert_eq!(2, f.stage().unwrap().len());
+
+            f.persist_stage().unwrap();
+            assert_eq!(3, f.events().unwrap().0.len());
+            assert_eq!(2, f.stage().unwrap().len());
+            tests::file_contains(&d, "plain", "enqueued");
+            tests::file_contains(&d, "plain", "new");
+
+            f.stage_persisted().unwrap();
+            assert_eq!(3, f.events().unwrap().0.len());
+            assert_eq!(2, f.stage().unwrap().len());
+            tests::file_contains(&d, "plain", "enqueued");
+            tests::file_contains(&d, "plain", "new");
+        });
+    }
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]