1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #pragma prototyped 23 /* 24 * Glenn Fowler 25 * AT&T Research 26 * 27 * Time_t conversion support 28 */ 29 30 #include <tmx.h> 31 32 static unsigned char offset[7][3] = 33 { 34 { 7, 6, 6 }, 35 { 1, 7, 7 }, 36 { 2, 1, 8 }, 37 { 3, 2, 9 }, 38 { 4, 3, 10}, 39 { 5, 4, 4 }, 40 { 6, 5, 5 }, 41 }; 42 43 /* 44 * type is week type 45 * 0 sunday first day of week 46 * 1 monday first day of week 47 * 2 monday first day of iso week 48 * if week<0 then return week for tm 49 * if day<0 then set tm to first day of week 50 * otherwise set tm to day in week 51 * and return tm->tm_yday 52 */ 53 54 int 55 tmweek(Tm_t* tm, int type, int week, int day) 56 { 57 int d; 58 59 if (week < 0) 60 { 61 if ((day = tm->tm_wday - tm->tm_yday % 7) < 0) 62 day += 7; 63 week = (tm->tm_yday + offset[day][type]) / 7; 64 if (type == 2) 65 { 66 if (!week) 67 week = (day > 0 && day < 6 || tmisleapyear(tm->tm_year - 1)) ? 53 : 52; 68 else if (week == 53 && (tm->tm_wday + (31 - tm->tm_mday)) < 4) 69 week = 1; 70 } 71 return week; 72 } 73 if (day < 0) 74 day = type != 0; 75 tm->tm_mon = 0; 76 tm->tm_mday = 1; 77 tmfix(tm); 78 d = tm->tm_wday; 79 tm->tm_mday = week * 7 - offset[d][type] + ((day || type != 2) ? day : 7); 80 tmfix(tm); 81 if (d = tm->tm_wday - day) 82 { 83 tm->tm_mday -= d; 84 tmfix(tm); 85 } 86 return tm->tm_yday; 87 } 88