if (hasSafariSignedIntBug && ms > maxSafeUnsigned32Bit) {
                    // work around a Safari 8/9 bug where it treats the seconds as signed
                    var msToShift = Math.floor(ms / maxSafeUnsigned32Bit) * maxSafeUnsigned32Bit;
                    var sToShift = Math.floor(msToShift / 1e3);
                    s += sToShift;