NAME
Time::Normalize - Convert time and date values into standardized components.
VERSION
This is version 0.02 of Normalize.pm, December 2, 2005.
SYNOPSIS
use Time::Normalize;
$hashref = normalize_ymd ($in_yr, $in_mo, $in_d);
($year, $mon, $day,
$dow, $dow_name, $dow_abbr,
$mon_name, $mon_abbr) = normalize_ymd ($in_yr, $in_mo, $in_dy);
$hashref = normalize_hms ($in_h, $in_m, $in_s, $in_ampm);
($hour, $min, $sec,
$h12, $ampm, $since_midnight)
= normalize_hms ($in_h, $in_m, $in_s, $in_ampm);
$hashref = normalize_time ($time_epoch);
($sec, $min, $hour,
$day, $mon, $year,
$dow, $yday, $isdst,
$h12, $ampm, $since_midnight,
$dow_name, $dow_abbr,
$mon_name, $mon_abbr) = normalize_time ($time_epoch);
$hashref = normalize_gmtime ($time_epoch);
@same_values_as_for_normalize_time = normalize_gmtime ($time_epoch);DESCRIPTION
Splitting a date into its component pieces is just the beginning.
Human date conventions are quirky (and I'm not just talking about the dates I've had!) Despite the Y2K near-disaster, some people continue to use two-digit year numbers. Months are sometimes specified as a number from 1-12, sometimes as a spelled-out name, sometimes as a abbreviation. Some months have more days than others. Humans sometimes use a 12-hour clock, and sometimes a 24-hour clock.
This module performs simple but tedious (and error-prone) checks on its inputs, and returns the time and/or date components in a sanitized, standardized manner, suitable for use in the remainder of your program.
Even when you get your values from a time-tested library function, such as localtime or gmtime, you need to do routine transformations on the returned values. The year returned is off by 1900 (for historical reasons); the month is in the range 0-11; you may want the month name or day of week name instead of numbers. The "normalize_time" function decodes localtime's values into commonly-needed formats.
FUNCTIONS
- normalize_ymd
-
$hashref = normalize_ymd ($in_yr, $in_mo, $in_d); ($year, $mon, $day, $dow, $dow_name, $dow_abbr, $mon_name, $mon_abbr) = normalize_ymd ($in_yr, $in_mo, $in_dy);Takes an arbitrary year, month, and day as input, and returns various data elements in a standard, consistent format. The output may be a hash reference or a list of values. If a hash reference is desired, the keys of that hash will be the same as the variable names given in the above synopsis; that is,
day,dow,dow_abbr,dow_name,mon,mon_abbr,mon_name, andyear.Input:
The input year may be either two digits or four digits. If two digits, the century is chosen so that the resulting four-digit year is closest to the current calendar year (i.e., within 50 years).
The input month may either be a number from 1 to 12, or a full month name as defined by the current locale, or a month abbreviation as defined by the current locale. If it's a name or abbreviation, case is not significant.
The input day must be a number from 1 to the number of days in the specified month and year.
If any of the input values do not meet the above criteria, an exception will be thrown. See "DIAGNOSTICS".
Output:
yearwill always be four digits.monthwill always be two digits, 01-12.daywill always be two digits 01-31.dowwill be a number from 0 (Sunday) to 6 (Saturday).dow_namewill be the name of the day of the week, as defined by the current locale, in the locale's preferred case.dow_abbrwill be the standard weekday name abbreviation, as defined by the current locale, in the locale's preferred case.mon_namewill be the month name, as defined by the current locale, in the locale's preferred case.mon_abbrwill be the standard month name abbreviation, as defined by the current locale, in the locale's preferred case. - normalize_hms
-
$hashref = normalize_hms ($in_h, $in_m, $in_s, $in_ampm); ($hour, $min, $sec, $h12, $ampm, $since_midnight) = normalize_hms ($in_h, $in_m, $in_s, $in_ampm);Like "normalize_ymd",
normalize_hmstakes a variety of possible inputs and returns standardized values. As above, the output may be a hash reference or a list of values. If a hash reference is desired, the keys of that hash will be the same as the variable names given in the above synopsis; that is,ampm,h12,hour,min,sec, andsince_midnight. Also, ah24key is provided as a synonym forhour.Input:
The input hour may either be a 12-hour or a 24-hour time value. If
$in_ampmis specified,$in_his assumed to be on a 12-hour clock, and if$in_ampmis absent,$in_his assumed to be on a 24-hour clock.The input minute must be numeric, and must be in the range 0 to 59.
The input second
$in_sis optional. If omitted, it defaults to 0. If specified, it must be in the range 0 to 59.The AM/PM indicator
$in_ampmis optional. If specified, it may be any of the following:a am a.m. p pm p.m. A AM A.M. P PM P.M.If any of the input values do not meet the above criteria, an exception will be thrown. See "DIAGNOSTICS".
Output:
hourThe first output hour will always be on a 24-hour clock, and will always be two digits, 00-23.minwill always be two digits, 00-59.secwill always be two digits, 00-59.h12is the 12-hour clock equivalent of$hour. It is not zero-padded.ampmwill always be either a lowercase 'a' or a lowercase 'p', no matter what format the input AM/PM indicator was, or even if it was omitted.since_midnightis the number of seconds since midnight represented by this time.h24is a key created if you request a hashref as the output; it's a synonym forhour. - normalize_time
-
$hashref = normalize_time($time_epoch); ($sec, $min, $hour, $day, $mon, $year, $dow, $yday, $isdst, $h12, $ampm, $since_midnight, $dow_name, $dow_abbr, $mon_name, $mon_abbr) = normalize_time($time_epoch);Takes a number in the usual perl epoch, passes it to localtime, and transforms the results. If
$time_epochis omitted, the current time is used instead.The output values (or hash values) are exactly as for "normalize_ymd" and "normalize_hms", above.
- normalize_gmtime
-
Exactly the same as normalize_time, but uses gmtime internally instead of localtime.
DIAGNOSTICS
The functions in this module throw exceptions (that is, they croak) whenever invalid arguments are passed to them. Therefore, it is generally a Good Idea to trap these exceptions with an eval block.
The error messages are meant to be easy to parse, if you need to. There are two kinds of errors thrown: data errors, and programming errors.
Data errors are caused by invalid data values; that is, values that do not conform to the expectations listed above. These messages all look like:
Time::Normalize: Invalid thing: "value"
Programming errors are caused by you--passing the wrong number of parameters to a function. These messages all look like:
Too {many|few} arguments to function_name
EXAMPLES
$h = normalize_ymd (2005, 'january', 4);
#
# Returns:
# $h{day} "04"
# $h{dow} 2
# $h{dow_abbr} "Tue"
# $h{dow_name} "Tuesday"
# $h{mon} "01"
# $h{mon_abbr} "Jan"
# $h{mon_name} "January"
# $h{year} 2005
# ------------------------------------------------
$h = normalize_ymd ('05', 12, 31);
#
# Returns:
# $h{day} 31
# $h{dow} 6
# $h{dow_abbr} "Sat"
# $h{dow_name} "Saturday"
# $h{mon} 12
# $h{mon_abbr} "Dec"
# $h{mon_name} "December"
# $h{year} 2005
# ------------------------------------------------
$h = normalize_ymd (2005, 2, 29);
#
# Throws an exception:
# Time::Normalize: Invalid day: "29"
# ------------------------------------------------
$h = normalize_hms (9, 10, 0, 'AM');
#
# Returns:
# $h{ampm} "a"
# $h{h12} 9
# $h{h24} "09"
# $h{hour} "09"
# $h{min} 10
# $h{sec} "00"
# $h{since_midnight} 33000
# ------------------------------------------------
$h = normalize_hms (9, 10, undef, 'p.m.');
#
# Returns:
# $h{ampm} "p"
# $h{h12} 9
# $h{h24} 21
# $h{hour} 21
# $h{min} 10
# $h{sec} "00"
# $h{since_midnight} 76200
# ------------------------------------------------
$h = normalize_hms (1, 10);
#
# Returns:
# $h{ampm} "a"
# $h{h12} 1
# $h{h24} "01"
# $h{hour} "01"
# $h{min} 10
# $h{sec} "00"
# $h{since_midnight} 4200
# ------------------------------------------------
$h = normalize_hms (13, 10);
#
# Returns:
# $h{ampm} "p"
# $h{h12} 1
# $h{h24} 13
# $h{hour} 13
# $h{min} 10
# $h{sec} "00"
# $h{since_midnight} 47400
# ------------------------------------------------
$h = normalize_hms (13, 10, undef, 'pm');
#
# Throws an exception:
# Time::Normalize: Invalid hour: "13"
# ------------------------------------------------
$h = normalize_gmtime(1131725587);
#
# Returns:
# $h{ampm} "p"
# $h{sec} "07",
# $h{min} 13,
# $h{hour} 16,
# $h{day} 11,
# $h{mon} 11,
# $h{year} 2005,
# $h{dow} 5,
# $h{yday} 314,
# $h{isdst} 0,
# $h{h12} 4
# $h{ampm} "p"
# $h{since_midnight} 58_387,
# $h{dow_name} "Friday",
# $h{dow_abbr} "Fri",
# $h{mon_name} "November",
# $h{mon_abbr} "Nov",
# ------------------------------------------------EXPORTS
This module exports the following symbols into the caller's namespace:
normalize_ymd
normalize_hms
normalize_time
normalize_gmtimeREQUIREMENTS
This module requires POSIX.
If I18N::Langinfo is available, this module will use it; otherwise, it will use hardcoded English values for month and weekday names.
Test::More is required for the test suite.
SEE ALSO
See Regexp::Common::time for a Regexp::Common plugin that matches nearly any date format imaginable.
BUGS
Uses Gregorian rules for computing whether a year is a leap year, no matter how long ago the year was.
NOT A BUG
By convention, noon is 12:00 pm; midnight is 12:00 am.
AUTHOR / COPYRIGHT
Eric J. Roode, roode@cpan.org
Copyright (c) 2005 by Eric J. Roode. All Rights Reserved. This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
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