diff --git a/config.json b/config.json
index 07259fa..8de61c0 100644
--- a/config.json
+++ b/config.json
@@ -6,9 +6,9 @@
         "{author['name']}"
       ],
       "filename": {
-        "locals().get('bitrate', 0) > 0": "{author['name']}-{tweet_id}-{date:Olocal/%Y%m%d_%H%M%S}-vid{num}.{extension}",
-        "locals().get('bitrate') == 0": "{author['name']}-{tweet_id}-{date:Olocal/%Y%m%d_%H%M%S}-gif{num}.{extension}",
-        "": "{author['name']}-{tweet_id}-{date:Olocal/%Y%m%d_%H%M%S}-img{num}.{extension}"
+        "locals().get('bitrate', 0) > 0": "{author['name']}-{tweet_id}-{date:%Y%m%d_%H%M%S}-vid{num}.{extension}",
+        "locals().get('bitrate') == 0": "{author['name']}-{tweet_id}-{date:%Y%m%d_%H%M%S}-gif{num}.{extension}",
+        "": "{author['name']}-{tweet_id}-{date:%Y%m%d_%H%M%S}-img{num}.{extension}"
       },
       "cookies": "$HOME/.config/gallery-dl/twitter-cookies.txt",
       "timeline": {
@@ -18,7 +18,7 @@
         {
           "name": "metadata",
           "event": "post",
-          "filename": "{author[name]}_{tweet_id}-{date:Olocal/%Y%m%d_%H%M%S}.json"
+          "filename": "{author['name']}-{tweet_id}-{date:%Y%m%d_%H%M%S}.json"
         }
       ]
     }
diff --git a/run-dedupeIds.js b/run-dedupeIds.js
new file mode 100644
index 0000000..509dbf5
--- /dev/null
+++ b/run-dedupeIds.js
@@ -0,0 +1,94 @@
+import { mkdir, readdir, rename } from 'fs/promises';
+
+import { getArg } from './lib/args.js';
+import { getChildDirectories } from './lib/io.js';
+import { error, log } from './lib/log.js';
+
+const ctx = 'dedupeIds.js';
+const idDateTimeRegex = new RegExp('([0-9]*)-(([0-9]{4})([0-9]{2})([0-9]{2}))_(([0-9]{2})([0-9]{2})([0-9]{2}))-((img|vid|gif)([0-9]*))');
+
+/**
+ * Reads through the db directory and looks for duplicate entries by id.
+ *
+ * If they have the same id, it will use the provided offset to determine which time is correct.
+ * - If `--offset="-"`, it will mark the file with the older date as a duplicate.
+ * - If `--offset="+"`, it will mark the file with the newer date as a duplicate.
+ * 
+ * This exists because `twittermediadownloader` used local time when saving files, which would possibly not be fixed because of DST.
+ * This repo uses UTC when saving times for the sake of consistency.
+ */
+const dedupeIds = async () => {
+  let directory, offset;
+  try {
+    directory = getArg('path');
+    offset = getArg('offset');
+  } catch (err) {
+    error(ctx, err);
+    return;
+  }
+
+  log(ctx, 'Reading directories');
+  const userDirs = await getChildDirectories(directory);
+
+  userDirs.forEach(async user => {
+    let workingDir = `${directory}/${user}`;
+    try {
+      await mkdir(`${workingDir}/dups`);
+    } catch (err) {
+      if (!err.toString().includes('EEXIST')) {
+        error(ctx, err);
+      }
+    }
+
+    log(ctx, `Finding dups for ${user}`);
+    const files = await readdir(workingDir);
+    const dupsToMove = [];
+
+    for (let i = 0; i < files.length; ++i) {
+      // Skip when the current file is already in dupsToMove
+      if (dupsToMove.includes(files[i])) {
+        continue;
+      }
+
+      // Go back/fourth ~5 images, as the max per post is 4; this should cover enough files without too much looping
+      let neighborMin = Math.min(Math.max(i - 5, 0), files.length - 1);
+      let neighborMax = Math.min(Math.max(i + 5, 0), files.length - 1);
+      for (let neighbor = neighborMin; neighbor < neighborMax; ++neighbor) {
+        if (dupsToMove.includes(files[neighbor]) || neighbor === i) {
+          continue;
+        }
+
+        // Test the neighbor and self for regex pattern id-date_time-typeCount.extension
+        let neighborTest = idDateTimeRegex.exec(files[neighbor]);
+        let selfTest = idDateTimeRegex.exec(files[i]);
+        if (!!neighborTest && !!selfTest) {
+          // If the id and the typeCount (e.g. img1 === img1) are the same, then the file is a dup
+          if (neighborTest[1] === selfTest[1] && neighborTest[10] === selfTest[10]) {
+            // Create dates from the date_time component of the files
+            let neighborDate = new Date(neighborTest[3], neighborTest[4], neighborTest[5], neighborTest[7], neighborTest[8], neighborTest[9]);
+            let selfDate = new Date(selfTest[3], selfTest[4], selfTest[5], selfTest[7], selfTest[8], selfTest[9]);
+
+            if (selfDate.getTime() > neighborDate.getTime() && offset.includes('-')) {
+              dupsToMove.push(files[neighbor]);
+              log(ctx, `${files[neighbor]} duplicate of ${files[i]}`);
+            } else {
+              dupsToMove.push(files[i]);
+              log(ctx, `${files[i]} duplicate of ${files[neighbor]}`);
+            }
+          }
+        }
+      }
+    }
+
+    log(ctx, `Moving dups for ${user}`);
+    dupsToMove.forEach(async dup => {
+      let dupMove = rename(`${workingDir}/${dup}`, `${workingDir}/dups/${dup}`);
+      dupMove.catch(err => error(ctx, err));
+      await dupMove;
+    });
+
+    log(ctx, `Moving finished for ${user}`);
+  });
+}
+
+dedupeIds();