Overpost Overview

The excess of time of the ** molad** over the first day of any month will be
referred to as the

The length of the molad periods for **1, 2 and 4 months** are

MOLAD PERIOD LENGTHS | |
---|---|

MONTHS | LENGTH |

1 | 29d 12h 793p |

2 | 59d 1h 506p |

4 | 118d 2h 1012p |

__Shevat's Overpost In A 383-Day Year__

383-DAY YEAR MAXIMUM OVERPOSTS | ||||
---|---|---|---|---|

KISLEV | SHEVAT |
|||

DAY | TIME | DAY | TIME | |

Maximum Molad of Tishrei |
Tishrei 1 | 2h 490p | Tishrei 1 | 2h 490p |

Molad Period From Tishrei | 59d | 1h 506p | 118d | 2h 1012p |

Maximum Molad Time |
Tishrei 60 | 3h 996p | Tishrei 119 | 5h 422p |

First Day of Month | Tishrei 60 | Tishrei 118 | ||

Maximum Overpost Possible | none | 5h 422p |

In any **383-day year**, the latest possible ** molad of Tishrei** is on

since

Hence, the maximum

In any

Hence, for the

__Kislev's Overpost In A 384-Day Year__

384-DAY YEAR MAXIMUM OVERPOSTS | ||||
---|---|---|---|---|

KISLEV | SHEVAT |
|||

DAY | TIME | DAY | TIME | |

Maximum Molad of Tishrei |
Tishrei 1 | 23h 1079p | Tishrei 1 | 23h 1079p |

Molad Period From Tishrei | 59d | 1h 506p | 118d | 2h 1012p |

Maximum Molad Time |
Tishrei 61 | 1h 505p | Tishrei 120 | 2h 1011p |

First Day of Month | Tishrei 60 | Tishrei 119 | ||

Maximum Overpost Possible | 1h 505p | 2h 1011p |

In any **384-day year**, the latest possible ** molad of Tishrei** is on

Hence, the maximum

In any

Hence, for the

__Shevat's Overpost In A 384-Day Year__

In any **384-day year**, the latest possible ** molad of Tishrei** is on

Hence, the maximum

In any

Hence, for the

__Dehiyah Molad Zaqen__

It is easily shown that no other month of the Hebrew calendar has any ** overpost**.

Therefore, the maximum

To avoid the ** overpost** problem for all possibilities, the

The Hebrew calendar scholars, possibly between years **4595H (835g)** and **4680H (920g)**, introduced with a limiting time of **18h**, the ** Tishrei 1** postponement rule known as

In **4680H (920g), Reb Aaron ben Meir** of Jerusalem wanted this limit upgraded to **18h 642p**, even though that value could have been as much as **18h 657p**.

**Saadia ben Yosef**, later to be known as **Saadia Gaon**, opposed **ben Meir's** change. Due to the infrequency of this calendar event (about once every **180 years** or so) the matter was forgotten sometimes after **4687H (927g)** and the **18h** limit remained intact, most probably because of its numerical simplicity. (See also The Ben Meir Years).

Please see Understanding *Dehiyah Molad Zaqen* for a more rigorous analysis of the ** overpost** problem.

First Paged 7 Nov 2006 Next Revised 22 Jan 2007