1 files changed, 52 insertions, 0 deletions
diff --git a/library/moment/src/lib/duration/iso-string.js b/library/moment/src/lib/duration/iso-string.js
new file mode 100644
index 000000000..f33a968da
--- /dev/null
+++ b/library/moment/src/lib/duration/iso-string.js
@@ -0,0 +1,52 @@
+import absFloor from '../utils/abs-floor';
+var abs = Math.abs;
+
+export function toISOString() {
+    // for ISO strings we do not use the normal bubbling rules:
+    //  * milliseconds bubble up until they become hours
+    //  * days do not bubble at all
+    //  * months bubble up until they become years
+    // This is because there is no context-free conversion between hours and days
+    // (think of clock changes)
+    // and also not between days and months (28-31 days per month)
+    var seconds = abs(this._milliseconds) / 1000;
+    var days         = abs(this._days);
+    var months       = abs(this._months);
+    var minutes, hours, years;
+
+    // 3600 seconds -> 60 minutes -> 1 hour
+    minutes           = absFloor(seconds / 60);
+    hours             = absFloor(minutes / 60);
+    seconds %= 60;
+    minutes %= 60;
+
+    // 12 months -> 1 year
+    years  = absFloor(months / 12);
+    months %= 12;
+
+
+    // inspired by https://github.com/dordille/moment-isoduration/blob/master/moment.isoduration.js
+    var Y = years;
+    var M = months;
+    var D = days;
+    var h = hours;
+    var m = minutes;
+    var s = seconds;
+    var total = this.asSeconds();
+
+    if (!total) {
+        // this is the same as C#'s (Noda) and python (isodate)...
+        // but not other JS (goog.date)
+        return 'P0D';
+    }
+
+    return (total < 0 ? '-' : '') +
+        'P' +
+        (Y ? Y + 'Y' : '') +
+        (M ? M + 'M' : '') +
+        (D ? D + 'D' : '') +
+        ((h || m || s) ? 'T' : '') +
+        (h ? h + 'H' : '') +
+        (m ? m + 'M' : '') +
+        (s ? s + 'S' : '');
+}