[LEAPSECS] Terminology question

Magnus Danielson magnus at rubidium.dyndns.org
Thu Mar 11 04:24:02 EST 2010

M. Warner Losh wrote:

> In message: <445CB57A-6FCF-4933-A288-BD152135229F at noao.edu>

> Rob Seaman <seaman at noao.edu> writes:

> : On Mar 10, 2010, at 10:12 PM, M. Warner Losh wrote:

> :

> : > Maybe we just need to toss the word 'idealized' in there somehow.

> : >

> : > time_t is an idealized representation of seconds since 1970.

> :

> : "Idealized representation" is a tautology.


> Actually, it isn't. If it were an actual representation, it would

> have leap seconds in it.

There are two aspects here, the leap seconds and the actual tracking
error. time_t tries to achieve two incompatible things at the same time,
but for all practical matters, implementers chooses to use the mapping
from the real UTC. time_t isn't looking like either TAI or UTC. It isn't
piece-wise linear, but it could maybe be said to be nominally piece-wise
linear to UTC. It's the closest I come right now.


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