Time::UTC::Now

Determine current time in UTC correctly
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Time::UTC::Now Ranking & Summary

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  • Rating:
  • License:
  • Perl Artistic License
  • Price:
  • FREE
  • Publisher Name:
  • Andrew Main
  • Publisher web site:
  • http://search.cpan.org/~zefram/

Time::UTC::Now Tags


Time::UTC::Now Description

Determine current time in UTC correctly Time::UTC::Now is a Perl module to determine current time in UTC correctly.SYNOPSIS use Time::UTC::Now qw(now_utc_rat now_utc_sna now_utc_flt); ($day, $secs, $bound) = now_utc_rat; ($day, $secs, $bound) = now_utc_rat(1); ($day, $secs, $bound) = now_utc_sna; ($day, $secs, $bound) = now_utc_sna(1); ($day, $secs, $bound) = now_utc_flt; ($day, $secs, $bound) = now_utc_flt(1); use Time::UTC::Now qw(utc_day_to_mjdn utc_day_to_cjdn); $mjdn = utc_day_to_mjdn($day); $cjdn = utc_day_to_cjdn($day);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 (Coordinated Universal Time) 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_mjdn function to translate to a standard Modified Julian Day Number or 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. Requirements: · Perl


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