Seriously, though, because this particular key chain is also a pocket watch you might consider using one of the suggestions regarding engravings on clocks, watches and sundials :

AGE QUOD AGIS – Do what you are doing

ALIIS INSERVIENDO CONSUMOR – By serving others, I am worn away Note that although originally a sundial inscription, this phrase actually makes a lot more sense for a clock mechanism, it also indicates a particular philosophy of life.

ARS LONGA, VITA BREVIS – Art lasts, life is short

ASPICE ET ABI – Look (at me) and pass on

DEO FAVENTE – With God’s favor

DEUS ADEST LABORANTIBUS – God favors the diligent

DIES DIEM TRUDIT – Each day forces out another day

DISCE DIES NUMERARE TUOS – Learn to value your days

DUM SPECTAS FUGIO – I flee even as you observe me

EX HOC MOMENTO PENDET AETERNITAS – Eternity is hinged upon this moment

FESTINA LENTE – Make haste slowly There is actually a company called Festina that makes clocks and watches. In my opinion, only the complete quote makes sense. Who would want a clock that is too fast? The phrase indicates a perfect balance that must be achieved in a clock and in life.

HINC VIVERE DISCE – Learn to live by this example

HORA PARS VITAE – Every hour is a part of life

ITA VITA – Thus (passes) life

LABOR IPSE VOLUPTAS – Labor contains pleasure

NE QUID PEREAT – Let nothing be lost

NON NOBIS NATI SUMUS – We are not born for ourselves

NON REDIBO – I shall not return

NOSCE TEIPSUM – Know thyself

OMNIA FALCE METIT TEMPUS – Time reaps everything with its sickle

OMNIA FERT AETAS – Time brings all things

POST TENEBRAS SPERO LUCEM – I hope for light after darkness

QUID CELERIUS TEMPORE? – What is swifter than time?

SAPIENTIS EST NUMERARE – It is the wise who count

SIC TRANSIT GLORIA MUNDI – Thus passes the glory of this world

ULTIMA DECIDET – The last one decides

UMBRA DEI – The shadow of God

VERITAS TEMPORIS FILIA – Truth is the daughter of time

VIGILATE & ORATE, TEMPUS FUGIT – Be vigilant and pray, for the time hastes away