//See /Doc/TimeDate.DD
U16 mon_start_days1[12]={
0,31,59,90,120,151,181,212,243,273,304,334};
U16 mon_start_days2[12]={
0,31,60,91,121,152,182,213,244,274,305,335};
I64 YearStartDate(I64 year)
{//32-bit day since AD 0, given year number.
I64 y1=year-1,yd4000=y1/4000,yd400=y1/400,yd100=y1/100,yd4=y1/4;
return year*365+yd4-yd100+yd400-yd4000;
}
CDate Struct2Date(CDateStruct *_ds)
{//Cvt CDateStruct to CDate.
CDate cdt;
I64 i1,i2;
i1=YearStartDate(_ds->year);
i2=YearStartDate(_ds->year+1);
if (i2-i1==365)
i1+=mon_start_days1[_ds->mon-1];
else
i1+=mon_start_days2[_ds->mon-1];
cdt.date=i1+_ds->day_of_mon-1;
cdt.time=(_ds->sec10000+100*(_ds->sec100+100*(_ds->sec
+60*(_ds->min+60*_ds->hour))))<<21/(15*15*3*625);
return cdt;
}
I64 DayOfWeek(I64 i)
{//Day of week, given 32-bit day since AD 0.
i+=CDATE_BASE_DAY_OF_WEEK;
if (i>=0)
return i % 7;
else
return 6-(6-i)%7;
}
U0 Date2Struct(CDateStruct *_ds,CDate cdt)
{//Cvt CDate to CDateStruct.
I64 i,k,date=cdt.date;
_ds->day_of_week=DayOfWeek(date);
_ds->year=(date+1)*100000/CDATE_YEAR_DAYS_INT;
i=YearStartDate(_ds->year);
while (i>date) {
_ds->year--;
i=YearStartDate(_ds->year);
}
date-=i;
if (YearStartDate(_ds->year+1)-i==365) {
k=0;
while (date>=mon_start_days1[k+1] && k<11)
k++;
date-=mon_start_days1[k];
} else {
k=0;
while (date>=mon_start_days2[k+1] && k<11)
k++;
date-=mon_start_days2[k];
}
_ds->mon=k+1;
_ds->day_of_mon=date+1;
k=(625*15*15*3*cdt.time)>>21+1;
_ds->sec10000=ModU64(&k,100);
_ds->sec100=ModU64(&k,100);
_ds->sec=ModU64(&k,60);
_ds->min=ModU64(&k,60);
_ds->hour =k;
}
I64 FirstDayOfMon(I64 i)
{//First day of month, given 32-bit day since AD 0.
CDateStruct ds;
CDate cdt=0;
cdt.date=i;
Date2Struct(&ds,cdt);
ds.day_of_mon=1;
cdt=Struct2Date(&ds);
return cdt.date;
}
I64 LastDayOfMon(I64 i)
{//Last day of month, given 32-bit day since AD 0.
CDateStruct ds;
CDate cdt=0;
cdt.date=i;
Date2Struct(&ds,cdt);
ds.mon++;
if (ds.mon==13) {
ds.mon=0;
ds.year++;
}
ds.day_of_mon=1;
cdt=Struct2Date(&ds);
return cdt.date-1;
}
I64 FirstDayOfYear(I64 i)
{//First day of year, given 32-bit day since AD 0.
CDateStruct ds;
CDate cdt=0;
cdt.date=i;
Date2Struct(&ds,cdt);
ds.day_of_mon=1;
ds.mon=1;
cdt=Struct2Date(&ds);
return cdt.date;
}
I64 LastDayOfYear(I64 i)
{//Last day of year, given 32-bit day since AD 0.
CDateStruct ds;
CDate cdt=0;
cdt.date=i;
Date2Struct(&ds,cdt);
ds.day_of_mon=1;
ds.mon=1;
ds.year++;
cdt=Struct2Date(&ds);
return cdt.date-1;
}
I64 Bcd2Bin(U64 b)
{
I64 i,res=0;
for (i=0;i<16;i++) {
res=res*10+b>>60;
b<<=4;
}
return res;
}
U0 NowDateTimeStruct(CDateStruct *_ds)
{
I64 i;
U8 *b=_ds;
Bool is_bcd;
MemSet(_ds,0,sizeof(CDateStruct));
PUSHFD
CLI
while (LBts(&sys_semas[SEMA_SYS_DATE],0))
PAUSE
OutU8(0x70,0x0A);
do {
while (InU8(0x71) & 0x80)
PAUSE
OutU8(0x70,0);
b[2]=InU8(0x71);
OutU8(0x70,2);
b[3]=InU8(0x71);
OutU8(0x70,4);
b[4]=InU8(0x71);
OutU8(0x70,6);
b[5]=InU8(0x71);
OutU8(0x70,7);
b[6]=InU8(0x71);
OutU8(0x70,8);
b[7]=InU8(0x71);
OutU8(0x70,9);
b[8]=InU8(0x71);
OutU8(0x70,0x0A);
} while (InU8(0x71) & 0x80);
OutU8(0x70,0x0B);
if (InU8(0x71) & 4)
is_bcd=FALSE;
else
is_bcd=TRUE;
LBtr(&sys_semas[SEMA_SYS_DATE],0);
POPFD
if (is_bcd)
for (i=2;i<9;i++)
b[i]=Bcd2Bin(b[i]);
if (_ds->year>255) _ds->year=255;
_ds->year+=2000;
if (_ds->mon>12) _ds->mon=12;
if (_ds->day_of_mon>31) _ds->day_of_mon=31;
if (_ds->day_of_week>6) _ds->day_of_week=6;
if (_ds->hour>23) _ds->hour=23;
if (_ds->min>59) _ds->min=59;
if (_ds->sec>59) _ds->sec=59;
}
CDate Now()
{//Current datetime.
CDateStruct ds;
NowDateTimeStruct(&ds);
return Struct2Date(&ds)-local_time_offset;
}