diff --git a/4chan_x.js b/4chan_x.js
index d0d201249..460957cdf 100644
--- a/4chan_x.js
+++ b/4chan_x.js
@@ -104,6 +104,7 @@
         'Anonymize': [false, 'Make everybody anonymous'],
         'Keybinds': [false, 'Binds actions to keys'],
         'Localize Time': [true, 'Show times based on your timezone'],
+        'Localized am/pm': [false, 'Change localized time to the 12-hour clock convention'],
         'Report Button': [true, 'Add report buttons'],
         'Comment Expansion': [true, 'Expand too long comments'],
         'Thread Expansion': [true, 'View all replies'],
@@ -1640,7 +1641,7 @@
   localize = {
     init: function() {
       return g.callbacks.push(function(root) {
-        var date, day, dotw, hour, min_sec, month, s, span, year, _, _i, _len, _ref, _ref2, _results;
+        var date, day, dotw, hour, meridiem, min_sec, month, s, span, year, _, _i, _len, _ref, _ref2, _results;
         _ref = $$('span[id^=no]', root);
         _results = [];
         for (_i = 0, _len = _ref.length; _i < _len; _i++) {
@@ -1650,13 +1651,18 @@
           year = "20" + year;
           month -= 1;
           hour = g.chanOffset + Number(hour);
+          meridiem = '';
+          if ($.config('Localized am/pm')) {
+            meridiem = hour < 12 ? ' a.m.' : ' p.m.';
+            hour = hour === 0 ? 12 : hour > 12 ? hour - 12 : void 0;
+          }
           date = new Date(year, month, day, hour);
           year = date.getFullYear() - 2000;
           month = $.zeroPad(date.getMonth() + 1);
           day = $.zeroPad(date.getDate());
           hour = $.zeroPad(date.getHours());
           dotw = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'][date.getDay()];
-          _results.push(s.textContent = " " + month + "/" + day + "/" + year + "(" + dotw + ")" + hour + ":" + min_sec + " ");
+          _results.push(s.textContent = " " + month + "/" + day + "/" + year + "(" + dotw + ")" + hour + ":" + min_sec + meridiem + " ");
         }
         return _results;
       });
diff --git a/script.coffee b/script.coffee
index 19c4fae5a..f85b9a4de 100644
--- a/script.coffee
+++ b/script.coffee
@@ -42,6 +42,7 @@ config =
       'Anonymize':         [false, 'Make everybody anonymous']
       'Keybinds':          [false, 'Binds actions to keys']
       'Localize Time':     [true,  'Show times based on your timezone']
+      'Localized am/pm':   [false, 'Change localized time to the 12-hour clock convention']
       'Report Button':     [true,  'Add report buttons']
       'Comment Expansion': [true,  'Expand too long comments']
       'Thread Expansion':  [true,  'View all replies']
@@ -1329,6 +1330,10 @@ localize =
         year = "20#{year}"
         month -= 1 #months start at 0
         hour = g.chanOffset + Number hour
+        meridiem = ''
+        if $.config 'Localized am/pm'
+          meridiem = if hour < 12 then ' a.m.' else ' p.m.'
+          hour = if hour is 0 then 12 else if hour > 12 then hour - 12
         date = new Date year, month, day, hour
         year = date.getFullYear() - 2000
         month = $.zeroPad date.getMonth() + 1
@@ -1343,7 +1348,7 @@ localize =
           'Fri'
           'Sat'
         ][date.getDay()]
-        s.textContent = " #{month}/#{day}/#{year}(#{dotw})#{hour}:#{min_sec} "
+        s.textContent = " #{month}/#{day}/#{year}(#{dotw})#{hour}:#{min_sec}#{meridiem} "
 
 titlePost =
   init: ->