NAME

Time::UTC::Now - determine current time in UTC correctly

DESCRIPTION

This module is one answer to the question "what time is it?".
It determines the current time on the UTC scale, handling leap seconds
correctly, and puts a bound on how inaccurate it could be.  It is the
rigorously correct approach to determining civil time.  It is designed
to interoperate with Time::UTC, which knows all about the UTC time scale.

UTC is a time scale derived from International Atomic Time (TAI).
UTC divides time up into days, and each day into seconds.  The seconds
are atomically-realised SI seconds, of uniform length.  Most UTC days
are exactly 86400 seconds long, but occasionally there is a day of length
86401 s or (theoretically) 86399 s.  These leap seconds are used to keep
the UTC day approximately synchronised with the non-uniform rotation
of the Earth.  (Prior to 1972 a different mechanism was used for UTC,
but that's not an issue here.)

Because UTC days have differing lengths, instants on the UTC scale
are identified here by the combination of a day number and a number of
seconds since midnight within the day.  In this module the day number
is the integral number of days since 1958-01-01, which is the epoch
of the TAI scale which underlies UTC.  This is the convention used
by the "Time::UTC" module.  That module has some functions to format
these numbers for display.  For a more general solution, use the
"utc_day_to_cjdn" function to translate to a standard Chronological
Julian Day Number, which can be used as input to a calendar module.

INSTALLATION

	perl Makefile.PL
	make
	make test
	make install

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

Copyright (C) 2006 Andrew Main (Zefram) <zefram@fysh.org>

This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
