# Decision table for determining the days in a month

**M1 = {**x: x is a 30-day month**}**

**M2 = {**x: x is a 31-day month**}**

**M3 = {**x: x is February**}**

conditions |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |

C1. Is month in M1 ? | T | T | T | T | T | T | T | T | F | F | F | F | F | F | F | F |

C2. Is month in M2 ? | T | T | T | T | F | F | F | F | T | T | T | T | F | F | F | F |

C3. Is month in M3 ? | T | T | F | F | T | T | F | F | T | T | F | F | T | T | F | F |

C4. Is year leap year ? | T | F | T | F | T | F | T | F | T | F | T | F | T | F | T | F |

A1. last day = 30 | x | x | ||||||||||||||

A2. last day = 31 | x | x | ||||||||||||||

A3. last day = 28 | x | |||||||||||||||

A4. last day = 29 | x | |||||||||||||||

A5. Impossible | x | x | x | x | x | x | x | x | x | x |

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