1 ;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
2 ;;;; *************************************************************************
3 ;;;; FILE IDENTIFICATION
5 ;;;; Name: datetime.lisp
6 ;;;; Purpose: Date & Time functions for KMRCL package
7 ;;;; Programmer: Kevin M. Rosenberg
8 ;;;; Date Started: Apr 2000
12 ;;;; This file, part of KMRCL, is Copyright (c) 2002 by Kevin M. Rosenberg
14 ;;;; KMRCL users are granted the rights to distribute and use this software
15 ;;;; as governed by the terms of the Lisp Lesser GNU Public License
16 ;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
17 ;;;; *************************************************************************
22 ;;; Formatting functions
24 (defun pretty-date (year month day &optional (hour 12) (m 0) (s 0))
25 (multiple-value-bind (sec min hr dy mn yr wkday)
26 (decode-universal-time
27 (encode-universal-time s m hour day month year))
28 (values (elt '("Monday" "Tuesday" "Wednesday" "Thursday"
29 "Friday" "Saturday" "Sunday")
31 (elt '("January" "February" "March" "April" "May" "June"
32 "July" "August" "September" "October" "November"
35 (format nil "~A" dy) (format nil "~A" yr)
36 (format nil "~2,'0D:~2,'0D:~2,'0D" hr min sec))))
39 (defun date-string (ut)
40 (if (typep ut 'integer)
41 (multiple-value-bind (sec min hr day mon year dow daylight-p zone)
42 (decode-universal-time ut)
43 (declare (ignore daylight-p zone))
44 (format nil "~[Mon~;Tue~;Wed~;Thu~;Fri~;Sat~;Sun~], ~d ~[Jan~;Feb~;Mar~;Apr~;May~;Jun~;Jul~;Aug~;Sep~;Oct~;Nov~;Dec~] ~d ~2,'0d:~2,'0d:~2,'0d"
51 (defun print-seconds (secs)
52 (print-float-units secs "sec"))
54 (defun print-float-units (val unit)
57 (format t "~,2,9F nano~A" val unit))
59 (format t "~,2,6F micro~A" val unit))
61 (format t "~,2,3F milli~A" val unit))
63 (format t "~,2,-9F giga~A" val unit))
65 (format t "~,2,-6F mega~A" val unit))
67 (format t "~,2,-3F kilo~A" val unit))
69 (format t "~,2F ~A" val unit))))
71 (defconstant +posix-epoch+
72 (encode-universal-time 0 0 0 1 1 1970 0))
74 (defun posix-time-to-utime (time)
75 (+ time +posix-epoch+))
77 (defun utime-to-posix-time (utime)
78 (- utime +posix-epoch+))
80 ;; Monthnames taken from net-telent-date to support lml2
96 (defun monthname (stream arg colon-p at-p &optional width (mincol 0) (colinc 1) (minpad 0) (padchar #\Space))
97 "Print the name of the month (1=January) corresponding to ARG on STREAM. This is intended for embedding in a FORMAT directive: WIDTH governs the number of characters of text printed, MINCOL, COLINC, MINPAD, PADCHAR work as for ~A"
98 (let ((monthstring (cdr (assoc arg *monthnames*))))
99 (if (not monthstring) (return-from monthname nil))
100 (let ((truncate (if width (min width (length monthstring)) nil)))
102 (if at-p "~V,V,V,V@A" "~V,V,V,VA")
103 mincol colinc minpad padchar
104 (subseq monthstring 0 truncate)))))
106 ;;;; Daylight Saving Time calculations
108 ;; Daylight Saving Time begins for most of the United States at 2
109 ;; a.m. on the first Sunday of April. Time reverts to standard time at
110 ;; 2 a.m. on the last Sunday of October. In the U.S., each time zone
111 ;; switches at a different time.
113 ;; In the European Union, Summer Time begins and ends at 1 am
114 ;; Universal Time (Greenwich Mean Time). It starts the last Sunday in
115 ;; March, and ends the last Sunday in October. In the EU, all time
116 ;; zones change at the same moment.
118 ;; Spring forward, Fall back
119 ;; During DST, clocks are turned forward an hour, effectively moving
120 ;; an hour of daylight from the morning to the evening.
122 ;; United States European Union
124 ;; Year DST Begins DST Ends Summertime Summertime
125 ;; at 2 a.m. at 2 a.m. period begins period ends
126 ;; at 1 a.m. UT at 1 a.m. UT
127 ;; ----------------------------------------------------------
128 ;; 2000 April 2 October 29 March 26 October 29
129 ;; 2001 April 1 October 28 March 25 October 28
130 ;; 2002 April 7 October 27 March 31 October 27
131 ;; 2003 April 6 October 26 March 30 October 26
132 ;; 2004 April 4 October 31 March 28 October 31
133 ;; 2005 April 3 October 30 March 27 October 30
134 ;; 2006 April 2 October 29 March 26 October 29
135 ;; 2007 April 1 October 28 March 25 October 28
136 ;; 2008 April 6 October 26 March 30 October 26