These alerts implement the traditional MACD (Moving Average Convergence Divergence) formula.  You can get a notification as soon as the MACD line crosses above or below the zero line or the signal line.  You can select the timeframe.  These alerts are based on the standard 26, 12, and 9 period EMAs.  These alerts report as soon as the value crosses, without waiting for the end of the candle.

Note:  because the MACD is based on the EMA (exponential moving average) formula, it is not deterministic.  Different charting packages will give slightly different values for the formula.  If you add more history to your chart, it might also change the result.  These values are generally similar, but they won't be exactly the same.