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;;; Library for handling dates in a PLIST format,
;;; like (:year 2009 :day 1 :month 3)
;;; Also provides a couple of utility time functions
;;; (c) Vsevolod Dyomkin <>. LICENSE: MIT
;;; NB: The library works properly only between years 1901 and 2099,
;;; because leap-year is calculated in a simplified manner
(defpackage :dates
(:use :common-lisp :cl-ppcre :rutils.usr)
(:export :*day-scanner*
(in-package :dates)
(declaim (inline date< date<= date> date>= print-date
day month year year-month year-month-d0
day/w week dow moy today ymd
leap-year-p beg-of-month month->str
str->month days-in-month))
;;; scanners
(defvar *day-scanner* (cl-ppcre:create-scanner "\\b\\d{1,2}\\b"))
(defvar *month-scanner* (cl-ppcre:create-scanner "\\b[a-zа-я]{3}\\b" :case-insensitive-mode t))
(defvar *year-scanner* (cl-ppcre:create-scanner "\\d{4}"))
;;; names
(defconstant =01-Jan-1901= 1) ; Tuesday
;; the lib will correctly calculate day-of-the-week (day/w) in the time
;; timeframe from 01-Jan-1901 to 31-Dec-2099
(defparameter *dow-dict*
'(:en #("Mon" "Tue" "Wed" "Thu" "Fri" "Sat" "Sun")
:ru #("пн" "вт" "ср" "чт" "пт" "сб" "вс")
:de #("Mon" "Die" "Mit" "Don" "Fri" "Son" "Sam")))
(defparameter *moy-dict*
'(:en #("January" "February" "March" "April" "May" "June" "July" "August" "September" "October" "November" "December")
:ru #("Январь" "Февраль" "Март" "Апрель" "Май" "Июнь" "Июль" "Август" "Сентябрь" "Октябрь" "Ноябрь" "Декабрь")
:de #("Januar" "Februar" "März" "April" "Mai" "Juni" "Juli" "August" "September" "October" "November" "Dezember")))
(defparameter *month-dict*
'(:en #("jan" "feb" "mar" "apr" "may" "jun" "jul" "aug" "sep" "oct" "nov" "dec")
:ru #("янв" "фев" "мар" "апр" "май" "июн" "июл" "авг" "сен" "окт" "ноя" "дек")
:de #("jan" "feb" "mär" "apr" "mai" "jun" "jul" "aug" "sep" "okt" "nov" "dez")))
(defvar *days-in-month*
#(31 28 31 30 31 30 31 31 30 31 30 31))
;;; testing
(defun datep (str-or-lst)
"True if STR-OR-LST is either in string date format D(D)-MMM-YYYY ~
or plist date format (:day d :month m :year y)"
(gcase ((type-of str-or-lst) :test #'subtypep)
('string (and (cl-ppcre:scan *day-scanner* str-or-lst)
(cl-ppcre:scan *month-scanner* str-or-lst)
(cl-ppcre:scan *year-scanner* str-or-lst)))
('list (and (plistp str-or-lst)
(getf str-or-lst :day)
(getf str-or-lst :month)
(getf str-or-lst :year)))))
(defun leap-year-p (date)
(= (nth-value 1 (floor (year date)
;;; conversion
(defun parse-date (string &optional (lang :en))
"Parsing the string with date, holding year (exactly 4 digits), ~
month (exactly 3 letters), day (exactly 2 digits) in any order, ~
separated with any separator with possible omition of any of the ~
following. If some of the values are omitted, they are substituted ~
with current ones"
(ignored1 ignored2 ignored3 current-day current-month current-year)
(list :year (or (parse-integer
(strcat (cl-ppcre:scan-to-strings *year-scanner* string)
" ")
:junk-allowed t)
:month (or (str->month (cl-ppcre:scan-to-strings *month-scanner*
:day (or (parse-integer
(strcat (cl-ppcre:scan-to-strings *day-scanner*
" ")
:junk-allowed t)
(defun print-date (date &optional (lang :en) stream)
(when date
(format stream "~4d~@[-~3a~]~@[-~2,'0d~]"
(getf date :year)
(month->str (getf date :month) lang)
(getf date :day))))
(defun print-numeric-date (date &optional stream)
(when date
(format stream "~4d~2,'0d~2,'0d"
(getf date :year)
(getf date :month)
(getf date :day))))
(defun str->month (str &optional (lang :en))
"Converting month in the form of 3-char string to number"
(when str
(dotimes (i 12)
(when (equalp str (aref (getf *month-dict* lang) i))
(return-from str->month (1+ i))))
(error "Wrong month name: ~a -- in language: ~a"
str lang)))
(defun month->str (num &optional (lang :en))
"Converting month in the form of number to 3-char string"
(when num
(aref (getf *month-dict* lang) (1- num))))
;;; date comparison
(defun date= (date1 date2 &rest dates)
(apply #'equalp date1 date2 dates))
(defun y-m= (date1 date2 &rest dates)
"Only check year and month"
(and (apply #'= (year date1) (year date2) (mapcar #'year dates))
(apply #'= (month date1) (month date2) (mapcar #'month dates))))
(defun date< (date1 date2)
((< (getf date1 :year) (getf date2 :year))
((= (getf date1 :year) (getf date2 :year))
(cond ((< (getf date1 :month) (getf date2 :month))
((= (getf date1 :month) (getf date2 :month))
(< (getf date1 :day) (getf date2 :day)))))))
(defun date<= (date1 date2)
(or (date< date1 date2) (date= date1 date2)))
(defun date> (date1 date2)
(date< date2 date1))
(defun date>= (date1 date2)
(date<= date2 date1))
;;; accessors
(defun day (date)
(getf date :day))
(defun month (date)
(getf date :month))
(defun year (date)
(getf date :year))
(defun year-month (date)
(list :year (year date) :month (month date)))
(defun year-month-d0 (date)
(list :year (year date) :month (month date) :day 0))
(defun today ()
(parse-date ""))
(defsetf day (date) (new-day)
`(setf (getf ,date :day) ,new-day))
(defsetf month (date) (new-month)
`(setf (getf ,date :month) ,new-month))
(defsetf year (date) (new-year)
`(setf (getf ,date :year) ,new-year))
;; adders
(defun day+ (date num)
(let* ((days-elapsed (+ (day date)
(beg-of-month date)))
(raw-day (+ days-elapsed num))
(days-in-year (if (leap-year-p date) 366 365))
(year (year date)))
((<= raw-day 0) (day+ `(:year ,(1- year) :month 12 :day 31)
(+ num days-elapsed)))
((> raw-day days-in-year) (day+ `(:year ,(1+ year) :month 1 :day 1)
(- raw-day days-in-year 1)))
(t (let ((month (loop for i to 11
with next-beg-of-month = 0
do (incf next-beg-of-month (aref *days-in-month* i))
when (and (leap-year-p date) (= i 1))
do (incf next-beg-of-month) ; leap-year
when (<= raw-day next-beg-of-month)
do (return (1+ i)))))
(list :year year
:month month
:day (- raw-day
(beg-of-month `(:year ,year :month ,month)))))))))
(defun month+ (date num)
"Try to return exactly the same day NUM months ahead (or behind). ~
If it's impossible, because of different month ending dates 28..31, ~
give that same date, but in an appropriate month (so 31-apr becomes 1-may etc)"
(multiple-value-bind (year-add raw-month) (floor (+ (month date) num -1) 12)
(let ((year (+ (year date) year-add)))
(nconc (list :year year)
(let ((raw-day (day date))
(max-day (+ (aref *days-in-month* raw-month)
(if (leap-year-p `(:year ,year)) 1 0))))
(if (> raw-day max-day)
(list :month (+ raw-month 2)
:day (- raw-day max-day))
(list :month (1+ raw-month)
:day raw-day)))))))
(defun year+ (date num)
"Try to return exactly the same day & month NUM years ahead (or behind). ~
For the case of 29-feb give 1-mar, if the year isn't a leap one"
(let ((new-year (+ (year date) num))
(month (month date))
(day (day date)))
(nconc (list :year new-year)
(if (and (not (leap-year-p `(:year ,new-year)))
(= day 29)
(= month 2))
(list :month 3 :day 1)
(list :month month :day day)))))
(defun week+ (date num)
(day+ date (* 7 num)))
;;; week specific
(defun beg-of-year/w (date)
"Return day-of-week number (starting from monday=0) of the ~
1st of January of the current year"
(let ((years-elapsed (- (year date) 1901)))
(nth-value 1 (floor (+ (* years-elapsed 365)
(floor years-elapsed 4)
(defun beg-of-month (date)
"Return number of days elapsed from the beginning of year, ~
until the beginning of the month, current to the given DATE"
(let ((month (1- (month date))))
(+ (reduce #'+ *days-in-month* :end month)
(if (and (> month 1) (leap-year-p date)) 1 0))))
(defun day/w (date)
"Return day of a week (number)"
(nth-value 1 (week date)))
#+ nil ;; alternative
(defun day/w (date)
(nth 6 (multiple-valuevalue-list
(encode-universal-time 0 0 0 (day date) (month date) (year date))))))
(defun week (date)
"Return number of the week, current to the given DATE. (Numbering ~
starts from 1), and a day of the week (in number format) of this DATE"
(multiple-value-bind (week day/w)
(floor (+ (day date)
(1- (beg-of-month date))
(beg-of-year/w date))
(values (1+ week) day/w)))
(defun dow (date &optional (lang :en))
"Return day of a week"
(aref (getf *dow-dict* lang)
(day/w date)))
(defun moy (date &optional (lang :en))
"Return month of a year"
(aref (getf *moy-dict* lang)
(1- (month date))))
(defun ymd (date)
"Return year-month-day of the DATE as multiple values"
(values (year date)
(month date)
(day date)))
;;; month specific
(defun next-month-end (&optional (tz-shift 0))
"return the end of next month, relatively to today, in the timezone, ~
specified by its TZ-SHIFT"
(let ((next-month (month+ (adjust-date (today) tz-shift) 1)))
(setf (day next-month) (elt *days-in-month* (1- (month next-month))))
(defun days-in-month (date)
(elt *days-in-month* (1- (dates:month date))))
;;; time functions
(defun adjust-date (date tz-shift)
"Adjust DATE according to TZ-SHIFT (+/- 1 day)"
(if (= tz-shift 0)
(let* ((decoded-time (multiple-value-list (get-decoded-time)))
(shift (+ tz-shift
(last1 decoded-time)))
(client-hour (+ (caddr decoded-time) shift)))
((< client-hour 0) (day+ date -1))
((> client-hour 23) (day+ date 1))
(t date)))))
(defun universal-to-unix-time (universal-time)
(- universal-time 2208988800))
(defun unix-to-universal-time (unix-time)
(+ unix-time 2208988800))
;;; end
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