A natural language date and time parser for Common Lisp.
Inspired by (and copied verbatim from) from Chronic, the natural language date and time parser for Ruby by Tom Preston-Werner.
To understand how Chronicity works, read this post: Writing a natural language date and time parser
Download and Installation
Or get the cutting-edge version from github: https://github.com/chaitanyagupta/chronicity/tree/master
Or get the latest stable release (usually updates before quicklisp): https://github.com/chaitanyagupta/chronicity/releases
CHRONICITY:PARSE to parse date/time strings.
*NOW* is not set, "now" is assumed to be this instant. All relative
date/time calculations are made with respect to
(setf chronicity:*now* (chronicity:make-datetime 2009 3 27 12 34 56)) => @2009-03-27T12:34:56.000000+05:30 (chronicity:parse "today") => @2009-03-27T13:00:00.000000+05:30 (chronicity:parse "tomorrow" :now (chronicity:make-date 2009 1 1)) => @2009-01-02T00:00:00.000000+05:30 (chronicity:parse "3 days from now") => @2009-03-30T12:34:56.000000+05:30 (chronicity:parse "next month") => @2009-04-01T00:00:00.000000+05:30
:ENDIAN-PREFERENCE indicates which date format to prefer in case of
ambiguity over days and months.
:LITTLE indicates the format
:MIDDLE indicates "mm/dd/yyy". Default is :LITTLE.
(chronicity:parse "1/2/2003") => @2003-02-01T00:00:00.000000+05:30 (chronicity:parse "1/2/2003" :endian-preference :middle) => @2003-01-02T00:00:00.000000+05:30
Default value for
(chronicity:parse "April 1st at 12:30 PM") => @2009-04-01T12:30:00.000000+05:30 (chronicity:parse "April 1st at 12:30 PM" :context :past) => @2008-04-01T12:30:00.000000+05:30
CHRONICITY:PARSE usually returns a DATETIME object. Its attributes can
be accessed using the datetime readers.
(chronicity:parse "next month" :guess :end) => @2009-04-30T23:59:59.000000+05:30 (values (chronicity:year-of *) (chronicity:month-of *) (chronicity:day-of *) (chronicity:hour-of *) (chronicity:minute-of *) (chronicity:sec-of *)) => 2009, 4, 30, 23, 59, 59
NIL as the value for
:GUESS returns a
SPAN, which is a range
of datetime values.
(chronicity:parse "next month" :guess nil) => #<CHRONICITY::SPAN 2009-04-01T00:00:00.000000+05:30...2009-05-01T00:00:00.000000+05:30> (values (chronicity:span-start *) (chronicity:span-end *) (chronicity:span-end-included-p *)) => @2009-04-01T00:00:00.000000+05:30, @2009-05-01T00:00:00.000000+05:30, NIL
Other possible values are
:END which return
the start, mid-point or the end of a span respectively.
thursday november summer friday 13:00 mon 2:35 4pm 6 in the morning friday 1pm sat 7 in the evening yesterday today tomorrow this tuesday next month this morning last night this second yesterday at 4:00 last friday at 20:00 last week tuesday tomorrow at 6:45pm afternoon yesterday thursday last week
3 years ago 5 months before now 7 hours ago 7 days from now 1 week hence in 3 hours 1 year ago tomorrow 3 months ago saturday at 5:00 pm 7 hours before tomorrow at noon 3rd wednesday in november 3rd month next year 3rd thursday this september 4th day last week
January 5 dec 25 may 27th October 2006 oct 06 jan 3 2010 february 14, 2004 3 jan 2000 17 april 85 5/27/1979 27/5/1979 05/06 1979-05-27 Friday 5 4:00 17:00 0800
Specific Times (many of the above with an added time)
January 5 at 7pm 1979-05-27 05:00:00 etc
Chronicity only works with the current timezone (as returned by
LOCAL-TIME:*DEFAULT-TIMEZONE*) . Support for different timezones is
planned for a future release.
The datetime object(s) returned by the parser are of type
LOCAL-TIME:TIMESTAMP. Be aware of any limitations that may apply to
Another problem is that parsing ordinals as words is supported except
second, which is ambiguous with second the unit of time. This
should be fixed in a future release.