1、這是當時我做的一個小小的課題，希望對你有所幫助#includestdio.h/*RequiredforMS-DOSuse#define ENTER0 x1C0D/* Enter key*/int year, month, day;staticchar*days8=,Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday;struct TIMEDATE intyear;/*year1980.2099*/ intmonth;/*month1=Jan2=Feb,day;/*dayofmonth0.31*/inthours;/*h

2、our0.23*/int minutes; /*minute0.59*/intseconds;/*second0.59inthsecs;/*1/100thsofsecond0.99*/ chardateline47;/*date&timetogether*/;static struct TIMEDATE today; main()char cmonth3; char cday3; char cyear5; double getdays();double daynumb, numbnow; intweekday,retcode,dayer,dayer = datetime(&today); cl

3、rscn();for (i=0;i3;+i)cmonthi=0; for (i=0;i3;+i)cdayi=0; for (i=0;i0)printf(nn%02d-%02d-%dwas,month,day,if (numbnow - daynumb 0)printf(nn%02d-%02d-%dwillbe,month,day,printf( a%sn,daysweekday);/* end MAIN */* GETDAYS-Fromintegervaluesofyear(YYYY),month*(MM)andday(DD)thissubroutinereturnsa*double floa

4、t number which represents the*number of days since Jan 1, 1980 (day 1).*This routine is the opposite of GETDATE.*/ double getdays(year, month, day)int year, month, day;int y,m;double a,b,d, daynumb; double floor(),intg();/* make correction for no year 0 */ if (year 0) y = year + 1;else y = year;/* J

5、an and Feb are months 13 and 14 in this calculation */ m = month;if (month 3)m = m + 12;y = y - 1;/* calculate Julian days */d = floor(365.25 * y) + intg(30.6001 * (m + 1) + day - 723244.0;/* use Julian calendar if before Oct 5, 1582 */ if (d -145068.0) daynumb =d;/* otherwise use Gregorian calendar

6、 */ elsea = floor(y / 100.0);b=2-a+floor(a/daynumb = d +b;return(daynumb); /* end GETDAYS */*GETDATE-Thisroutinetakesadoublefloatnumber*representingthenumberofdayssinceJan1,*1980(day1)andreturnstheyearmonthand*dayaspointerintegers*This routine is the opposite of GETDAYS*/ getdate(numb)double numb;do

7、uble doubledate;date = numb;z=intg(date+2444239.0); if(date13.5)month=e-13.0;else month = e - 1.0;if(month2)year=c-else year = c -4715.0;if(year28000.0)dd=dd-28000.0; while(dd0)dd=dd+28000.0;day = dd;day=(day+1)%7)+return(day);/* FRACT -This routine takes a double float number*andreturnsthefractiona

8、lpartasadouble*float number*/ double fract(numb)double numb;int inumb; double while(numb32767)numb-=32767; inumb =numb;fnumb = inumb; return(numb-fnumb); /* end FRACT */* FLOOR -This routine takes a double float number*and returns the next smallest integer*/ double floor(numb)double numb;double fract(), intg(); double out;out = intg(numb);if (numb 0 & fract(numb) != 0) out -= 1.0; return(out); /* end FLOOR */* INTG-*This routine takes a double float numberand re