A Galic Lunar Calendar

Using Month Names From the Coligny Tablet

Gallic time-keeping is discussed in the RBO page on The Coligny Tablet.

The following table is my own attempt to understand the calendar outlined on the Coligny tablet, and shows all occurrences of the full-moon over a thirty year period between November 24AD and October 54AD. The numbered 'Cycles' are purely arbitrary, and are not based on any recognised epoch. Togodumnus.


Month 1st Cycle2nd Cycle3rd Cycle4th Cycle5th Cycle6th Cycle7th Cycle8th Cycle9th Cycle10th Cycle
Samonios - Samhain 5 Nov 24AD25 Oct 25AD15 Oct 26AD 3 Nov 27AD22 Oct 28AD10 Nov 29AD30 Oct 30AD19 Oct 31AD 6 Nov 32AD26 Oct 33AD
Dumannios 4 Dec 24AD24 Nov 25AD13 Nov 26AD 3 Dec 27AD21 Nov 28AD10 Dec 29AD28 Nov 30AD17 Nov 31AD 5 Dec 32AD25 Nov 33AD
Riuros 3 Jan 25AD23 Dec 25AD13 Dec 26AD 1 Jan 28AD21 Dec 28AD 8 Jan 30AD28 Dec 30AD17 Dec 31AD 4 Jan 33AD24 Dec 33AD
Anagantios - Oimelc 2 Feb 25AD22 Jan 26AD11 Jan 27AD30 Jan 28AD19 Jan 29AD 7 Feb 30AD27 Jan 31AD16 Jan 32AD 3 Feb 33AD23 Jan 34AD
Ogronios 3 Mar 25AD20 Feb 26AD10 Feb 27AD29 Feb 28AD18 Feb 29AD 8 Mar 30AD25 Feb 31AD15 Feb 32AD 4 Mar 33AD21 Feb 34AD
Cutios 2 Apr 25AD22 Mar 26AD11 Mar 27AD29 Mar 28AD19 Mar 29AD 6 Apr 30AD27 Mar 31AD15 Mar 32AD 3 Apr 33AD23 Mar 34AD
MidSamonios   10 Apr 27AD 17 Apr 29AD  14 Apr 32AD  
Giamonios - Beltane 2 May 25AD21 Apr 26AD 9 May 27AD28 Apr 28AD17 May 29AD 6 May 30AD25 Apr 31AD13 May 32AD 3 May 33AD22 Apr 34AD
Simivisionios 31 May 25AD20 May 26AD 8 Jun 27AD27 May 28AD15 Jun 29AD 4 Jun 30AD25 May 31AD12 Jun 32AD 1 Jun 33AD21 May 34AD
Equos 30 Jun 25AD19 Jun 26AD 8 Jul 27AD26 Jun 28AD14 Jul 29AD 3 Jul 30AD23 Jun 31AD11 Jul 32AD 1 Jul 33AD20 Jun 34AD
Elembuios - Lughnasadh 29 Jul 25AD19 Jul 26AD 6 Aug 27AD25 Jul 28AD13 Aug 29AD 2 Aug 30AD22 Jul 31AD 9 Aug 32AD30 Jul 33AD19 Jul 34AD
Edrinios 28 Aug 25AD17 Aug 26AD 5 Sep 27AD24 Aug 28AD12 Sep 29AD31 Aug 30AD21 Aug 31AD 8 Sep 32AD28 Aug 33AD18 Aug 34AD
Cantlos 26 Sep 25AD16 Sep 26AD 4 Oct 27AD23 Sep 28AD11 Oct 29AD30 Sep 30AD19 Sep 31AD 7 Oct 32AD27 Sep 33AD16 Sep 34AD
Month 11th Cycle12th Cycle13th Cycle14th Cycle15th Cycle16th Cycle17th Cycle18th Cycle19th Cycle20th Cycle
Samonios - Samhain 16 Oct 34AD 4 Nov 35AD24 Oct 36AD12 Nov 37AD 1 Nov 38AD21 Oct 39AD 8 Nov 40AD28 Oct 41AD18 Oct 42AD 6 Nov 43AD
Dumannios 14 Nov 34AD 4 Dec 35AD23 Nov 36AD12 Dec 37AD 1 Dec 38AD20 Nov 39AD 8 Dec 40AD27 Nov 41AD16 Nov 42AD 5 Dec 43AD
Riuros 14 Dec 34AD 2 Jan 36AD22 Dec 36AD10 Jan 38AD30 Dec 38AD20 Dec 39AD 6 Jan 41AD26 Dec 41AD16 Dec 42AD 4 Jan 44AD
Anagantios - Oimelc 13 Jan 35AD 1 Feb 36AD20 Jan 37AD 9 Feb 38AD29 Jan 39AD18 Jan 40AD 5 Feb 41AD25 Jan 42AD14 Jan 43AD 2 Feb 44AD
Ogronios 11 Feb 35AD 1 Mar 36AD19 Feb 37AD10 Mar 38AD28 Feb 39AD17 Feb 40AD 7 Mar 41AD24 Feb 42AD13 Feb 43AD 3 Mar 44AD
Cutios 13 Mar 35AD31 Mar 36AD20 Mar 37AD 8 Apr 38AD29 Mar 39AD18 Mar 40AD 5 Apr 41AD26 Mar 42AD15 Mar 43AD 1 Apr 44AD
MidSamonios 11 Apr 35AD 19 Apr 37AD  16 Apr 40AD  13 Apr 43AD 
Giamonios - Beltane 11 May 35AD29 Apr 36AD18 May 37AD 8 May 38AD27 Apr 39AD15 May 40AD 5 May 41AD24 Apr 42AD12 May 43AD¹ 1 May 44AD
Simivisionios 10 Jun 35AD29 May 36AD17 Jun 37AD 6 Jun 38AD27 May 39AD14 Jun 40AD 3 Jun 41AD24 May 42AD11 Jun 43AD31 May 44AD
Equos 9 Jul 35AD27 Jun 36AD16 Jul 37AD 5 Jul 38AD25 Jun 39AD13 Jul 40AD 3 Jul 41AD22 Jun 42AD11 Jul 43AD29 Jun 44AD
Elembuios - Lughnasadh 8 Aug 35AD27 Jul 36AD15 Aug 37AD 4 Aug 38AD24 Jul 39AD11 Aug 40AD 1 Aug 41AD22 Jul 42AD 9 Aug 43AD29 Jul 44AD
Edrinios 6 Sep 35AD26 Aug 36AD13 Sep 37AD 2 Sep 38AD23 Aug 39AD10 Sep 40AD30 Aug 41AD20 Aug 42AD 8 Sep 43AD27 Aug 44AD
Cantlos 6 Oct 35AD24 Sep 36AD13 Oct 37AD 2 Oct 38AD21 Sep 39AD 9 Oct 40AD29 Sep 41AD18 Sep 42AD 7 Oct 43AD26 Sep 44AD
Month21st Cycle 22nd Cycle23rd Cycle24th Cycle25th Cycle26th Cycle27th Cycle28th Cycle29th Cycle30th Cycle
Samonios - Samhain 25 Oct 44AD13 Nov 45AD 3 Nov 46AD23 Oct 47AD11 Oct 48AD30 Oct 49AD19 Oct 50AD 7 Nov 51AD27 Oct 52AD16 Oct 53AD
Dumannios 24 Nov 44AD13 Dec 45AD 2 Dec 46AD22 Nov 47AD 9 Nov 48AD28 Nov 49AD18 Nov 50AD 7 Dec 51AD25 Nov 52AD15 Nov 53AD
Riuros 23 Dec 44AD11 Jan 46AD 1 Jan 47AD21 Dec 47AD 9 Dec 48AD28 Dec 49AD17 Dec 50AD 5 Jan 52AD25 Dec 52AD14 Dec 53AD
Anagantios - Oimelc 22 Jan 45AD10 Feb 46AD30 Jan 47AD20 Jan 48AD 8 Jan 49AD27 Jan 50AD16 Jan 51AD 4 Feb 52AD23 Jan 53AD13 Jan 54AD
Ogronios 20 Feb 45AD11 Mar 46AD 1 Mar 47AD18 Feb 48AD 7 Feb 49AD26 Feb 50AD15 Feb 51AD 4 Mar 52AD22 Feb 53AD11 Feb 54AD
Cutios 22 Mar 45AD10 Apr 46AD30 Mar 47AD19 Mar 48AD 8 Mar 49AD27 Mar 50AD16 Mar 51AD 3 Apr 52AD23 Mar 53AD13 Mar 54AD
MidSamonios      7 Apr 49AD 15 Apr 51AD  11 Apr 54AD
Giamonios - Beltane 20 Apr 45AD 9 May 46AD29 Apr 47AD17 Apr 48AD 6 May 49AD26 Apr 50AD15 May 51AD 3 May 52AD22 Apr 53AD10 May 54AD
Simivisionios 20 May 45AD 7 Jun 46AD28 May 47AD17 May 48AD 5 Jun 49AD25 May 50AD13 Jun 51AD 1 Jun 52AD21 May 53AD 9 Jun 54AD
Equos 18 Jun 45AD 7 Jul 46AD26 Jun 47AD15 Jun 48AD 4 Jul 49AD24 Jun 50AD12 Jul 51AD 1 Jul 52AD20 Jun 53AD 9 Jul 54AD
Elembuios - Lughnasadh 16 Aug 45AD 6 Aug 46AD26 Jul 47AD14 Jul 48AD 2 Aug 49AD23 Jul 50AD11 Aug 51AD30 Jul 52AD20 Jul 53AD 7 Aug 54AD
Edrinios 15 Sep 45AD 4 Sep 46AD24 Aug 47AD13 Aug 48AD 1 Sep 49AD21 Aug 50AD 9 Sep 51AD29 Aug 52AD18 Aug 53AD 6 Sep 54AD
Cantlos 15 Oct 45AD 4 Oct 46AD23 Sep 47AD11 Sep 48AD30 Sep 49AD20 Sep 50AD 9 Oct 51AD27 Sep 52AD17 Sep 53AD 6 Oct 54AD

¹ The full-moon on the 12th May 43AD is significant because it represented the probable date of the fire-festival of Beltain. This was an important time in the iron-age year, a religious holiday during which all ritual warfare ceased. It is particularly of note because it may be the date on which Aulus Plautius actually initiated the Roman invasion of Britain.


The data in the above table was compiled using the superb RedShift3 software from Maris Multimedia, and published by Dorling Kindersley; any mistakes are my own.