NAME

Time::Clock - Twenty-four hour clock object with nanosecond precision.

SYNOPSIS

  $t = Time::Clock->new(hour => 12, minute => 34, second => 56);
  print $t->as_string; # 12:34:56

  $t->parse('8pm');
  print "$t"; # 20:00:00

  print $t->format('%I:%M %p'); # 08:00 PM

  $t->add(minutes => 15, nanoseconds => 123000000);
  print $t->as_string; # 20:15:00.123

  $t->subtract(hours => 30);
  print $t->as_string; # 14:15:00.123

  ...

DESCRIPTION

A Time::Clock object is a twenty-four hour clock with nanosecond precision and wrap-around. It is a clock only; it has absolutely no concept of dates. Vagaries of date/time such as leap seconds and daylight savings time are unsupported.

When a Time::Clock object hits 23:59:59.999999999 and at least one more nanosecond is added, it will wrap around to 00:00:00.000000000. This works in reverse when time is subtracted.

Time::Clock objects automatically stringify to a user-definable format.

CLASS METHODS

default_format FORMAT: Set the default format used by the as_string method for all objects of this class. Defaults to "%H:%M:%S%n". See the documentation for the format method for a complete list of format specifiers.
Note that this method may also be called as an object method, in which case it sets the default format for the individual object only.

CONSTRUCTOR

new PARAMS

Constructs a new Time::Clock object based on PARAMS, where PARAMS are name/value pairs. Any object method is a valid parameter name. Example:

    $t = Time::Clock->new(hour => 12, minute => 34, second => 56);

If a single argument is passed to new, it is equivalent to calling the parse method. That is, this:

    $t = Time::Clock->new('12:34:56');

is equivalent to this:

    $t = Time::Clock->new;
    $t->parse('12:34:56');

Returns the newly constructed Time::Clock object.

OBJECT METHODS

add PARAMS: Add the time specified by PARAMS to the clock. Valid PARAMS are:

"hours INT": An integer number of hours.
"minutes INT": An integer number of minutes.
"seconds INT": An integer number of seconds.
"nanoseconds INT": An integer number of nanoseconds.

If the amount of time added is large enough, the clock will wrap around from 23:59:59.999999999 to 00:00:00.000000000 as needed.

ampm AM/PM

Get or set the AM/PM attribute of the clock. Valid values of AM/PM must contain the letters "AM" or "PM" (case-insensitive), optionally followed by periods.

A clock whose hour is greater than 12 cannot be set to AM. Any attempt to do so will cause a fatal error.

Setting a clock whose hour is less than 12 to PM will cause its hour to be increased by 12. Example:

    $t = Time::Clock->new('8:00');
    print $t->as_string; # 08:00:00

    $t->ampm('PM');
    print $t->as_string; # 20:00:00

Return the string "AM" if the hour is less than 12, "PM" otherwise.

as_integer_seconds

Returns the integer number of seconds since 00:00:00.

as_string

Returns a string representation of the clock, formatted according to the clock object's default_format.

default_format FORMAT

Set the default format used by the as_string method for this object. Defaults to "%H:%M:%S%n". See the documentation for the format method for a complete list of format specifiers.

Note that this method may also be called as a class method, in which case it sets the default format all objects of this class.

format FORMAT

Returns the clock value formatted according to the FORMAT string containing "%"-prefixed format specifiers. Valid format specifiers are:

%H

The hour as a two-digit, zero-padded integer using a 24-hour clock (range 00 to 23).

%I

The hour as a two-digit, zero-padded integer using a 12-hour clock (range 01 to 12).

%i

The hour as an integer using a 12-hour clock (range 1 to 12).

%k

The hour as an integer using a 24-hour clock (range 0 to 23).

%M

The minute as a two-digit, zero-padded integer (range 00 to 59).

%n

If the clock has a non-zero nanosecond value, then this format produces a decimal point followed by the fractional seconds up to and including the last non-zero digit. If no nanosecond value is defined, or if it is zero, then this format produces an empty string. Examples:

    $t = Time::Clock->new('12:34:56');
    print $t->format('%H:%M:%S%n'); # 12:34:56

    $t->nanosecond(0);
    print $t->format('%H:%M:%S%n'); # 12:34:56

    $t->nanosecond(123000000);
    print $t->format('%H:%M:%S%n'); # 12:34:56.123

"%[1-9]n"

If the clock has a defined nanosecond value, then this format produces a decimal point followed by the specified number of digits of fractional seconds (1-9). Examples:

    $t = Time::Clock->new('12:34:56');
    print $t->format('%H:%M:%S%4n'); # 12:34:56

    $t->nanosecond(0);
    print $t->format('%H:%M:%S%4n'); # 12:34:56.0000

    $t->nanosecond(123000000);
    print $t->format('%H:%M:%S%4n'); # 12:34:56.1230

%N

Nanoseconds as a nine-digit, zero-padded integer (range 000000000 to 999999999)

"%[1-9]N"

Fractional seconds as a one- to nine-digit, zero-padded integer. Examples:

    $t = Time::Clock->new('12:34:56');
    print $t->format('%H:%M:%S.%4N'); # 12:34:56.0000

    $t->nanosecond(123000000);
    print $t->format('%H:%M:%S.%6N'); # 12:34:56.123000

    $t->nanosecond(123000000);
    print $t->format('%H:%M:%S.%2N'); # 12:34:56.12

%p

Either "AM" or "PM" according to the value return by the ampm method.

%P

Like %p but lowercase: "am" or "pm"

%S

The second as a two-digit, zero-padded integer (range 00 to 61).

%s

The integer number of seconds since 00:00:00.

%T

The time in 24-hour notation (%H:%M:%S).

"%%"

A literal "%" character.

hour INT

Get or set the hour of the clock. INT must be an integer from 0 to 23.

minute INT

Get or set the minute of the clock. INT must be an integer from 0 to 59.

nanosecond INT

Get or set the nanosecond of the clock. INT must be an integer from 0 to 999999999.

parse STRING

Set the clock time by parsing STRING. The invoking object is returned.

Valid string values contain an hour with optional minutes, seconds, fractional seconds, and AM/PM string. There should be a colon (":") between hours, minutes, and seconds, and a decimal point (".") between the seconds and fractional seconds. Fractional seconds may contain up to 9 digits. The AM/PM string is case-insensitive and may have periods after each letter.

The string "now" will initialize the clock object with the current (local) time. If the Time::HiRes module is installed, this time will have fractional seconds.

A time value with an hour of 24 and zero minutes, seconds, and nanoseconds is also accepted by this method.

Here are some examples of valid time strings:

    12:34:56.123456789
    12:34:56.123 PM
    24:00
    8:30pm
    6 A.m.
    now

second INT

Get or set the second of the clock. INT must be an integer from 0 to 59.

subtract PARAMS

Subtract the time specified by PARAMS from the clock. Valid PARAMS are:

"hours INT": An integer number of hours.
"minutes INT": An integer number of minutes.
"seconds INT": An integer number of seconds.
"nanoseconds INT": An integer number of nanoseconds.

If the amount of time subtracted is large enough, the clock will wrap around from 00:00:00.000000000 to 23:59:59.999999999 as needed.

AUTHOR

John C. Siracusa (siracusa@gmail.com)