/*** *ctime.h - constant for dates and times * * Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved. * *Purpose: * Include file used by the c time routines containing definitions of * various constants and macros used in determining dates and times. * * [Internal] * *Revision History: * 03-??-84 RLB written * 05-??-84 DFW split out the constant from each routine into this file * 07-27-89 GJF Fixed copyright * 10-30-89 GJF Fixed copyright (again) * 02-28-90 GJF Added #ifndef _INC_CTIME stuff. * 03-29-93 GJF Revised constants. * 02-14-95 CFW Clean up Mac merge. * 03-29-95 CFW Add error message to internal headers. * 12-14-95 JWM Add "#pragma once". * 02-24-97 GJF Detab-ed. * 05-07-97 GJF Added _MAX_YEAR64 and _MAX_TIME64_T constants. Added * _IS_LEAP_YEAR() and _ELAPSED_LEAP_YEAR macros. Took * out unnecessary casts. * 02-09-98 GJF Changes for Win64: removed unnecessary typing of * constants as long, also put in larger value for * _MAX_YEAR. * 12-10-99 GB _MAX_YEAR for Win64 be equal to _MAX_YEAR64 * ****/ #if _MSC_VER > 1000 /*IFSTRIP=IGN*/ #pragma once #endif #ifndef _INC_CTIME #define _INC_CTIME #ifndef _CRTBLD /* * This is an internal C runtime header file. It is used when building * the C runtimes only. It is not to be used as a public header file. */ #error ERROR: Use of C runtime library internal header file. #endif /* _CRTBLD */ /* * Constants */ #define _DAY_SEC (24 * 60 * 60) /* secs in a day */ #define _YEAR_SEC (365 * _DAY_SEC) /* secs in a year */ #define _FOUR_YEAR_SEC (1461 * _DAY_SEC) /* secs in a 4 year interval */ #define _DEC_SEC 315532800 /* secs in 1970-1979 */ #define _BASE_YEAR 70 /* 1970 is the base year */ #define _BASE_DOW 4 /* 01-01-70 was a Thursday */ #define _LEAP_YEAR_ADJUST 17 /* Leap years 1900 - 1970 */ #ifdef _WIN64 #define _MAX_YEAR 1099 /* 2999 is the max year */ #else #define _MAX_YEAR 138 /* 2038 is the max year */ #endif #define _MAX_YEAR64 1099 /* 2999 is the max year */ #define _MAX__TIME64_T 0x100000000000i64 /* number of seconds from 00:00:00, 01/01/1970 UTC to 23:59:59. 12/31/2999 UTC */ /* * Macro to determine if a given year, expressed as the number of years since * 1900, is a leap year. */ #define _IS_LEAP_YEAR(y) (((y % 4 == 0) && (y % 100 != 0)) || \ ((y + 1900) % 400 == 0)) /* * Number of leap years from 1970 up to, but not including, the specified year * (expressed as the number of years since 1900). */ #define _ELAPSED_LEAP_YEARS(y) (((y - 1)/4) - ((y - 1)/100) + ((y + 299)/400) \ - _LEAP_YEAR_ADJUST) #endif /* _INC_CTIME */