Glossary

There is a great deal of specialised terminology associated with timekeeping and its associated disciplines. When introducing a new word or concept to the journal for the first time I'll try and give a definition or some examples; thereafter it's definition can be found here.

astronomy
The study of the motions and properties of the stars and planets.

archeoastronomy
The study of the astronomical alignment of ancient man-made structures.

chronology
The sequencing of past events.

chronometry
The measurement of time.

computus
The computation of the date of Easter in the Christian calendar. The original "computers" were Christian monks who spent long periods of time making this calculation.

epoch
An arbitary point in time from which other points are measured. Often used to designate the beginning of a calendar system.

horology
The study of clockmaking, clocks, watches and chronometers.

isochronism
To recur at a fixed time interval. The property of having a uniform period of oscillation regardless of amplitude or periodicity. See: Building an accurate Timekeeper in AS3, Building an accurate Timekeeper in AS3 II , Building an accurate Timekeeper in AS3 III

leap day and leap second
A single unit that is inserted into the normal period of timekeeping in order to synchronise the system with the revolution of the earth.

marine chronometer
An accurate portable timekeeper.

proleptic calendar
Applying the rules of a calendar system to the period before it came into use.

temporal drift
The difference between a clock or timekeepers expected time and its actual time. See: Building an accurate Timekeeper in AS3 .