NAME

Date::Extract - extract probable dates from strings

SYNOPSIS

    my $parser = Date::Extract->new();
    my $dt = $parser->extract($arbitrary_text)
        or die "No date found.";
    return $dt->ymd;

MOTIVATION

There are already a few modules for getting a date out of a string. DateTime::Format::Natural should be your first choice. There's also Time::ParseDate which fits many formats. Finally, you can coerce Date::Manip to do your bidding.

But I needed something that will take an arbitrary block of text, search it for something that looks like a date string, and extract it. This module fills this niche. By design it will produce few false positives. This means it will not catch nearly everything that looks like a date string. So if you have the string "do homework for class 2019" it won't return a DateTime object with the year set to 2019. This is what your users would probably expect.

METHODS

new PARAMHASH => Date::Extract

arguments

format

Choose what format the extracted date(s) will be. The default is "DateTime", which will return DateTime object(s). Other option include "verbatim" (return the original text), or "epoch" (return Unix timestamp).

time_zone

Only relevant when format is set to "DateTime".

Forces a particular time zone to be set (this actually matters, as "tomorrow" on Monday at 11 PM means something different than "tomorrow" on Tuesday at 1 AM).

By default it will use the "floating" time zone. See the documentation for DateTime.

This controls both the input time zone and output time zone.

prefers

This argument decides what happens when an ambiguous date appears in the input. For example, "Friday" may refer to any number of Fridays. The valid options for this argument are:

nearest

Prefer the nearest date. This is the default.

future

Prefer the closest future date.

past

Prefer the closest past date. NOT YET SUPPORTED.

returns

If the text has multiple possible dates, then this argument determines which date will be returned. By default it's 'first'.

first

Returns the first date found in the string.

last

Returns the final date found in the string.

earliest

Returns the date found in the string that chronologically precedes any other date in the string.

latest

Returns the date found in the string that chronologically follows any other date in the string.

all

Returns all dates found in the string, in the order they were found in the string.

all_cron

Returns all dates found in the string, in chronological order.

extract text, ARGS => dates

Takes an arbitrary amount of text and extracts one or more dates from it. The return value will be zero or more dates, which by default are DateTime objects (but can be customized with the format argument). If called in scalar context, only one will be returned, even if the returns argument specifies multiple possible return values.

See the documentation of new for the configuration of this method. Any arguments passed into this method will trump those from the constructor.

You may reuse a parser for multiple calls to extract.

You do not need to have an instantiated Date::Extract object to call this method. Just Date::Extract->extract($foo) will work.

FORMATS HANDLED

• today; tomorrow; yesterday

• last Friday; next Monday; previous Sat

• Monday; Mon

• November 13th, 1986; Nov 13, 1986

• 13 November 1986; 13 Nov 1986

• November 13th; Nov 13

• 13 Nov; 13th November

• 1986/11/13; 1986-11-13

• 11-13-86; 11/13/1986

CAVEATS

This module is intentionally very simple. Surprises are not welcome here.

SEE ALSO

DateTime::Format::Natural, Time::ParseDate, Date::Manip

AUTHOR

Shawn M Moore, <sartak at bestpractical dot com>

ACKNOWLEDGEMENTS

Thanks to Steven Schubiger for writing the fine DateTime::Format::Natural. We still use it, but it doesn't quite fill all the particular needs we have.

COPYRIGHT & LICENSE

Copyright 2007-2009 Best Practical Solutions.

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