Second Chronology

Definition and standing

The Second Chronology is a subsidiary chronology within the Tower, certified by the Chronology Guild and calibrated, as a matter of routine practice, against the Tower Standard Chronology. It is the dating system in which the greater part of the Tower's Concordances are expressed, and its years are the units in which most formal promulgations, annexes, and disciplinary findings are recorded. Unlike the Fifth Chronology and the Central Chronology, both of which are derived wholly from the Tower Standard Chronology, the Second Chronology retains a small residual reckoning of its own — a habit of the scriptoria rather than a rule of the Guild.

The Second Chronology is not, despite its ordinal, the second chronology established in the Tower. The Primary Chronology holds that distinction, and the Stairwell Chronology claims it under protest. The numbering reflects the order of surviving certification rolls, not the order of use.

Relation to the Tower Standard Chronology

Under the calibration adopted by the College of Applied Chronology and confirmed in the Promulgation of Harmonized Chronology, one Tower Standard Chronology year is defined as one Second Chronology year, with a fixed offset applied at the point of promulgation. The offset is recorded in the Standard Amended Chronology and has been amended eleven times, most recently in Year 402 of the Second Chronology itself — a circularity that the Verification of Chronology office has flagged twice without resolving.

The Librarians' recorded chronology is maintained independently of the Tower Standard Chronology and, by extension, independently of the Second Chronology. Records kept under the Incident Chronology are likewise exempt. This exemption is the source of considerable confusion in readers who expect a date given in the Second Chronology to align with a date given in any other system; it does not, and the discrepancy is not an error.

Chronological scope

The Second Chronology begins at Year 1, which is not defined as the beginning of anything. The Guild's certification roll states only that Year 1 is the first year for which a complete set of Concordance witnesses survives. Prior to that point, dating is handled under the Non Linear Chronology provisions first set out in the marginalia of the Second Concordance, and later adopted by the Guild for readings on Floor 7,117.

No upper bound has been recorded. The highest attested year is Year 1,244, appearing in a single marginal note on Floor 11,902 and not corroborated by any other document. The Standard Tower Chronology working group has declined to treat it as a terminus.

Disputed points

The relationship between the Second Chronology and the Fourth Concordance, Appendix Omega remains contested. Appendix Omega was drafted in Year 91 of the Second Chronology and bound by the sewn method, yet its internal dating clause refers to a year count that begins thirty-one years earlier than the certification roll allows. Two offices have offered reconciliations; neither has been promulgated.

A second dispute concerns annexes appended to documents dated in the Second Chronology but themselves written under a different system. Annex Gamma 7, formally appended to the Second Concordance in Year 23 of the Second Chronology, carries a marginal date in the Fifth Chronology that converts to a year two years earlier than the appending record. The Verification of Chronology office has twice requested a correction and twice been told the discrepancy is intentional.

Practical notes

Readers citing the Second Chronology are reminded that Year 1 of the Second Chronology does not correspond to Year 1 of the Central Chronology, and that the conversion tables held on Floors 340 and 341 are printed on different scales and should not be used together. Chalk marks left by surveyors on the stair landings between Floors 880 and 895 are dated in the Second Chronology and are refreshed each twelfth year; they are not, as sometimes assumed, permission to leave further marks.

See also

• Tower Standard Chronology
• Non Linear Chronology
• Chronology Guild
• Second Concordance
• Verification of Chronology