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 conversion support 28 */ 29 30 #include <ast.h> 31 #include <tm.h> 32 33 #define DAYS(p) (tm_data.days[(p)->tm_mon]+((p)->tm_mon==1&&LEAP(p))) 34 #define LEAP(p) (tmisleapyear((p)->tm_year)) 35 36 /* 37 * correct out of bounds fields in tm 38 * 39 * tm_isdst is not changed -- call tmxmake() to get that 40 * 41 * tm is the return value 42 */ 43 44 Tm_t* 45 tmfix(register Tm_t* tm) 46 { 47 register int n; 48 register int w; 49 Tm_t* p; 50 time_t t; 51 52 /* 53 * check for special case that adjusts tm_wday at the end 54 * this happens during 55 * nl_langinfo() => strftime() => tmfmt() 56 */ 57 58 if (w = !tm->tm_sec && !tm->tm_min && !tm->tm_mday && !tm->tm_year && !tm->tm_yday && !tm->tm_isdst) 59 { 60 tm->tm_year = 99; 61 tm->tm_mday = 2; 62 } 63 64 /* 65 * adjust from shortest to longest units 66 */ 67 68 if ((n = tm->tm_sec) < 0) 69 { 70 tm->tm_min -= (60 - n) / 60; 71 tm->tm_sec = 60 - (-n) % 60; 72 } 73 else if (n > (59 + TM_MAXLEAP)) 74 { 75 tm->tm_min += n / 60; 76 tm->tm_sec %= 60; 77 } 78 if ((n = tm->tm_min) < 0) 79 { 80 tm->tm_hour -= (60 - n) / 60; 81 n = tm->tm_min = 60 - (-n) % 60; 82 } 83 if (n > 59) 84 { 85 tm->tm_hour += n / 60; 86 tm->tm_min %= 60; 87 } 88 if ((n = tm->tm_hour) < 0) 89 { 90 tm->tm_mday -= (23 - n) / 24; 91 tm->tm_hour = 24 - (-n) % 24; 92 } 93 else if (n >= 24) 94 { 95 tm->tm_mday += n / 24; 96 tm->tm_hour %= 24; 97 } 98 if (tm->tm_mon >= 12) 99 { 100 tm->tm_year += tm->tm_mon / 12; 101 tm->tm_mon %= 12; 102 } 103 else if (tm->tm_mon < 0) 104 { 105 tm->tm_year--; 106 if ((tm->tm_mon += 12) < 0) 107 { 108 tm->tm_year += tm->tm_mon / 12; 109 tm->tm_mon = (-tm->tm_mon) % 12; 110 } 111 } 112 while (tm->tm_mday < -365) 113 { 114 tm->tm_year--; 115 tm->tm_mday += 365 + LEAP(tm); 116 } 117 while (tm->tm_mday > 365) 118 { 119 tm->tm_mday -= 365 + LEAP(tm); 120 tm->tm_year++; 121 } 122 while (tm->tm_mday < 1) 123 { 124 if (--tm->tm_mon < 0) 125 { 126 tm->tm_mon = 11; 127 tm->tm_year--; 128 } 129 tm->tm_mday += DAYS(tm); 130 } 131 while (tm->tm_mday > (n = DAYS(tm))) 132 { 133 tm->tm_mday -= n; 134 if (++tm->tm_mon > 11) 135 { 136 tm->tm_mon = 0; 137 tm->tm_year++; 138 } 139 } 140 if (w) 141 { 142 w = tm->tm_wday; 143 t = tmtime(tm, TM_LOCALZONE); 144 p = tmmake(&t); 145 if (w = (w - p->tm_wday)) 146 { 147 if (w < 0) 148 w += 7; 149 tm->tm_wday += w; 150 if ((tm->tm_mday += w) > DAYS(tm)) 151 tm->tm_mday -= 7; 152 } 153 } 154 tm->tm_yday = tm_data.sum[tm->tm_mon] + (tm->tm_mon > 1 && LEAP(tm)) + tm->tm_mday - 1; 155 n = tm->tm_year + 1900 - 1; 156 tm->tm_wday = (n + n / 4 - n / 100 + n / 400 + tm->tm_yday + 1) % 7; 157 158 /* 159 * tm_isdst is adjusted by tmtime() 160 */ 161 162 return tm; 163 } 164