diff --git a/config.js b/config.js
index a58554a..96c56f8 100644
--- a/config.js
+++ b/config.js
@@ -24,6 +24,10 @@
  *                 mm     minute 00-59        (35) - lowercase!
  *                 ss     second 00-59        (22) - lowercase!
  *                 sss    millisecond 000-999 (456)
+ *                 a      am/pm (lowercase)   (pm)
+ *                 A      AM/PM (uppercase)   (PM)
+ *                 aaaa   am/pm lowercase        (pm) - long form
+ *                 AAAA   AM/PM uppercase        (PM) - long form
  *                 T      literal 'T'
  *
  *               Non-standard extension tokens (localized via i18n):
diff --git a/index.html b/index.html
index b4a326b..80d6d3e 100644
--- a/index.html
+++ b/index.html
@@ -897,6 +897,22 @@ var effect = (VANTA.CLOUDS2 || VANTA.CLOUDS)({
                 } else if (ch === 's' && format.substr(i, 2) === 'ss') {
                     result += pad2(date.getSeconds());
                     i += 2;
+                } else if (ch === 'a' && format.substr(i, 4) === 'aaaa') {
+                    // Full am/pm text (lowercase)
+                    result += date.getHours() < 12 ? 'am' : 'pm';
+                    i += 4;
+                } else if (ch === 'A' && format.substr(i, 4) === 'AAAA') {
+                    // Full AM/PM text (uppercase)
+                    result += date.getHours() < 12 ? 'AM' : 'PM';
+                    i += 4;
+                } else if (ch === 'a') {
+                    // am/pm (lowercase)
+                    result += date.getHours() < 12 ? 'am' : 'pm';
+                    i += 1;
+                } else if (ch === 'A') {
+                    // AM/PM (uppercase)
+                    result += date.getHours() < 12 ? 'AM' : 'PM';
+                    i += 1;
                 } else {
                     result += ch;
                     i += 1;