⚠The lower portion of this page contains a bluish-green stain, likely from historical liquid damage or a pigment wash, though the text remains largely legible beneath it.

[Calendar: January]

In the upper margin, a medieval illustration depicts the "Labors of the Months." For January, we see the two-faced god Janus—from whom the month takes its name—seated at a feast, looking both back at the old year and forward to the new. Beside him, a youth warms himself by a hearth where a pot boils, a domestic scene emphasizing the need for warmth and food during the height of winter.

January has 31 days; the lunar month has 30.

Golden NumberA number from 1 to 19 used to determine the phase of the moon and calculate the date of Easter.	Dominical LetterLetters A through G assigned to days to help identify the day of the week for any given date.	Day	Feast / Event
	A	Kalends	JANUARY Circumcision of the Lord The feast celebrating the circumcision of Jesus, eight days after his birth.
III	B	4th	Octave of Saint Stephen An "Octave" is the eighth day after a major feast, often concluding a week of celebration.
	C	3rd	Octave of Saint John. Saint Genevieve, virgin. Saint Genevieve is the patron saint of Paris.
XI	D	2nd	Octave of the Holy Innocents.
XIX	E	Nones	The "Nones" was a marker in the Roman calendar, usually the 5th or 7th day of the month.
VIII	F	8th	Epiphany of the Lord Celebrating the visit of the Magi.
	G	7th
XVI	A	6th	Lucian, Maximian, and Julian, martyrs.
V	B	5th
	C	4th
XIII	D	3rd
II	E	2nd
	F	Ides
X	G	19th	IDES Octave of Epiphany and Saint Hilary, bishop. The "Ides" was a marker in the Roman calendar, usually falling on the 13th or 15th of the month. Roman dates after the Ides count backward from the "Kalends" (the 1st) of the next month.
	A	18th	Felix, priest.
XVIII	B	17th	Saint Maurus, abbot.
VII	C	16th	Marcellus, pope.
	D	15th	Sulpicius and Anthony, bishops.
XV	E	14th	Prisca, virgin.
IV	F	13th	Launomarus, abbot.
	G	12th	Fabian and Sebastian. Saint Mary and Martha with companions.
XII	A	11th	Saint Agnes, virgin and martyr.
I	B	10th	Saint Vincent, martyr.
	C	9th	Emerentiana, virgin and martyr.
IX	D	8th	Conversion of Saint Paul. Commemorates the miraculous conversion of the Apostle Paul on the road to Damascus.
	E	7th
XVII	F	6th	Saint Julian, bishop.
VI	G	5th	Saint Agnes, for the second time. original: "Agnetis secundo." A second celebration of Agnes, usually commemorating an appearance she made to her parents after her death.
	A	4th
XIV	B	3rd	Saint Bathild, queen. A 7th-century queen of France known for her piety and for abolishing the slave trade of Christians.
III	C	2nd