1 files changed, 21 insertions, 0 deletions
diff --git a/library/moment/src/lib/duration/add-subtract.js b/library/moment/src/lib/duration/add-subtract.js
new file mode 100644
index 000000000..3b44e186f
--- /dev/null
+++ b/library/moment/src/lib/duration/add-subtract.js
@@ -0,0 +1,21 @@
+import { createDuration } from './create';
+
+function addSubtract (duration, input, value, direction) {
+    var other = createDuration(input, value);
+
+    duration._milliseconds += direction * other._milliseconds;
+    duration._days         += direction * other._days;
+    duration._months       += direction * other._months;
+
+    return duration._bubble();
+}
+
+// supports only 2.0-style add(1, 's') or add(duration)
+export function add (input, value) {
+    return addSubtract(this, input, value, 1);
+}
+
+// supports only 2.0-style subtract(1, 's') or subtract(duration)
+export function subtract (input, value) {
+    return addSubtract(this, input, value, -1);
+}