count down timer diff is long within milliseconds

countdown.java

/*Observable.interval(1, TimeUnit.SECONDS)
                .take((int) (diff/SECOND_IN_MILLIS))
                .flatMap(new Func1<Long, Observable<String>>() {
                    @Override
                    public Observable<String> call(Long aLong) {
                        long millisUntilFinished = diff - aLong * SECOND_IN_MILLIS;
                        long day = millisUntilFinished / (24 * 60 * 60 * SECOND_IN_MILLIS);
                        long hour = (millisUntilFinished / (60 * 60 * SECOND_IN_MILLIS) - day * 24);
                        long min = ((millisUntilFinished / (60 * SECOND_IN_MILLIS)) - day * 24 * 60 - hour * 60);
                        long s = (millisUntilFinished / SECOND_IN_MILLIS - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60);
                        return Observable.just("" + day + "天" + hour + "小时" + min + "分" + s + "秒");
                    }
                })
                .observeOn(AndroidSchedulers.mainThread())
                .compose(this.<String>bindToLifecycle())
                .subscribe(new BaseSubscriber<String>() {
                    @Override
                    protected void onError(ApiException ex) {
                        ToastUtil.showShort(mContext, ex.message);
                    }

                    @Override
                    public void onCompleted() {
//                        mBinding.tvLeftTime.setText("done!");
                    }

                    @Override
                    public void onNext(String result) {
                        mBinding.tvLeftTime.setText(result);
                    }
                });*/