When do we use this formula?

In fact, there are many cases need to use this formula to solve the problem!

Suppose you have a row contains day have the event, and you want to count how many events on Monday!

**Example:**

A | B | |

Weekday | Event | |

1 | Mon | Event |

2 | Mon | Event |

3 | Sat | Event |

4 | Web | Event |

5 | Sat | Event |

6 | Tue | Event |

7 | Tue | Event |

8 | Thu | Event |

Try to use: `=SUMPRODUCT(--(WEEKDAY(A1,A8)=1))`

The result is **2**, 1 is Monday.

We have general formula: `=SUMPRODUCT(--(WEEKDAY(dates)=day_num))`

**dates**are range that has to contain weekday.**day_num**is numbered 1-7 for the days Monday-Sunday