diff --git a/index.html b/index.html
index d1025af..1405c93 100644
--- a/index.html
+++ b/index.html
@@ -188,6 +188,26 @@
 </form>
 
 <script type="text/javascript">
+dayjs.extend(dayjs_plugin_utc);
+dayjs.extend(dayjs_plugin_timezone);
+dayjs.extend(dayjs_plugin_duration);
+dayjs.extend(dayjs_plugin_relativeTime);
+
+const Timer = {
+    setTimestamp: (reset=false) => {
+        $('#uptimeLabel').dataset.timestamp = dayjs().unix();
+        if (reset) $('#uptimeLabel').dataset.timedelta = 0;
+    },
+    setTimedelta: () => {
+        $('#uptimeLabel').dataset.timedelta = Timer.getTimedelta().asSeconds();
+    },
+    getTimedelta: () => {
+        let timedelta = dayjs.duration(dayjs().diff(dayjs.unix($('#uptimeLabel').dataset.timestamp)));
+        let sum = dayjs.duration($('#uptimeLabel').dataset.timedelta||0, 'second').add(timedelta);
+        return sum;
+    },
+};
+
 const $ = (selectors) => {
     return document.querySelector(selectors);
 };
@@ -245,6 +265,7 @@ $$$('#send', 'click', async (e) => {
 
             Connection.send(JSON.stringify(parameters));
             Status = 'RUNNING';
+            Timer.setTimestamp(true);
 
             $('#send > span.text').innerHTML = 'Pause';
             $('#send > span.icon').classList.remove('hidden');
@@ -278,7 +299,6 @@ $$$('#send', 'click', async (e) => {
                 Status = 'READY';
 
                 $('#fileLabel').innerHTML = file.name;
-                $('#uptimeLabel').dataset.seconds = 0;
                 $('#send > span.text').innerHTML = 'Send';
                 $('#cancel').disabled = false;
                 $('#send').disabled = true;
@@ -444,6 +464,7 @@ function main(url, parameters, locales) {
             case 'setStatus':
                 switch (args[0]) {
                     case 'RESUME':
+                        Timer.setTimestamp();
                     case 'BYPASS':
                         Status = 'RUNNING';
                         $('#send').disabled = false;
@@ -452,6 +473,7 @@ function main(url, parameters, locales) {
                     case 'ONHOLD':
                         Status = 'STANDBY';
                         $('#send').disabled = false;
+                        Timer.setTimedelta();
                         break;
                     case 'FAILED':
                         Status = 'STANDBY';
@@ -491,11 +513,6 @@ function main(url, parameters, locales) {
         }
     });
 
-    dayjs.extend(dayjs_plugin_utc);
-    dayjs.extend(dayjs_plugin_timezone);
-    dayjs.extend(dayjs_plugin_duration);
-    dayjs.extend(dayjs_plugin_relativeTime);
-
     let clock = setInterval(() => {
         let timezone = $('#timezoneLabel').dataset.timezone;
         let city = timezone.split('/')[1];
@@ -510,16 +527,15 @@ function main(url, parameters, locales) {
             let percentage = parseFloat((index / limit * 100).toFixed(2));
             $('#progressLabel').innerHTML = `${index} / ${limit} (${percentage} %)`;
 
-            let uptime = dayjs.duration($('#uptimeLabel').dataset.seconds, 'second');
+            let uptime = Timer.getTimedelta();
+            $('#uptimeLabel').innerHTML = uptime.format("HH:mm:ss");
+
             let rate = Number($('#progressLabel').dataset.sent) / uptime.asSeconds();
             let spm = parseFloat(Number(rate*60).toFixed(2));
-
             $('#remainingLabel').innerHTML = rate > 0 ? `<span>${dayjs.duration((limit - index) / rate, 'second').humanize()}</span>` : '';
             $('#remainingLabel').innerHTML += spm >= 1 ? `<span class="${spm > 8.33 ? 'rate warning' : 'rate'}">${spm} per minute</span>` : '';
-            $('#uptimeLabel').innerHTML = uptime.format("HH:mm:ss");
-            $('#uptimeLabel').dataset.seconds = uptime.asSeconds() + 1;
         }
-    }, 1000);
+    }, 500);
 }
 </script>
 
diff --git a/main.py b/main.py
index c3c88c9..c8ba2ea 100644
--- a/main.py
+++ b/main.py
@@ -293,6 +293,11 @@ def main(driver: WebDriver):
         recipients = data.get(parameters.get('column_address'), [])
         limit = len(recipients)
 
+        if not limit:
+            tell('输入无效', filename, level=1)
+            outbox.put(Command('setStatus', 'FINISH'))
+            continue
+
         names = data.get(parameters.get('column_name'), [None] * limit)
         codes = data.get(parameters.get('column_code'), [None] * limit)
         sents = data.setdefault(parameters.get('column_sent'), [None] * limit)