The Therin calendar is somewhat unusual in that, instead of numbering years sequentially by adding 1 to each passing year, it proceeds in 12 year cycles, with each god of The Twelve having a year named for them in each cycle. So instead of year 1 being followed by year 2, we get the 77th year of Gandolo being followed by the 77th year of Morgante. Assuming this has been consistent from the beginning, the Therin calendar has been in place for more than 900 years.
To complicate matters further, it appears that the order in which the gods occur in each cycle may not be fixed. For example, Locke Lamora is found by the Thiefmaker in the 77th year of Gandolo. At the time he is five or six. This is followed by the 77th year of Morgante, when he would be six or seven. Locke is initiated into the mysteries of the Crooked Warden under the Orphan's Moon, his 13th birthday, in the 77th year of Aza Guilla. So in the 77th cycle, Morgante came before Aza Guilla. This seems to change in the 78th cycle. The Lies of Locke Lamora takes place during the 78th year of Aza Guilla. Red Seas Under Red Skies is set two years or so later in what is, according to the master's log aboard the Red Messenger, the 78th year or Morgante. Meaning in the 78th cycle the order has changed, placing Morgante about two years after Aza Guilla instead of seven or eight years before.
- 77th year of Gandolo - The Thiefmaker brings Locke out of Catchfire following an outbreak of the Black Whisper.
- 77th year of Morgante - 6 months after his arrival at Shade's Hill, Locke accidentally gets the Elderglass Vine tavern burned down.
- 77th year of Sendovani - Locke is sold to Father Chains.
- 77th year of Iono - Two years after Locke is sold to Chains, Jean Tannen is sold to him as well.
- 77th year of Aza Guilla - Locke turns 13 and is chosen to become a priest of the Nameless Thirteenth.
- 78th year of Preva - Locke is 16. The Gentlemen Bastards put on a production of Lucarno's "The Republic of Thieves."
- 78th year of Aza Guilla - Most of The Lies of Locke Lamora takes place. The Gray King arrives to take revenge on Camorr.
- 78th year of Nara - Jean visits Azura Gallardine of Tal Verrar's artificer's guild. Locke visits Salon Corbeau.
- 78th year of Morgante - The majority of Red Seas Under Red Skies takes place. Locke and Jean rob Requin. Maxilan Stragos, the last Archon of Tal Verrar, falls.