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-rw-r--r--src/date.c146
1 files changed, 122 insertions, 24 deletions
diff --git a/src/date.c b/src/date.c
index e493542db..059d4c88a 100644
--- a/src/date.c
+++ b/src/date.c
@@ -1237,21 +1237,97 @@ static void dateFunc(
}
/*
+** Compute the one-based day of the year for the DateTime pDate.
+** Jan01 = 1, Jan02 = 2, ... Dec31 = 356 or 366.
+*/
+static int dayOfYear(DateTime *pDate){
+ DateTime jan01 = *pDate;
+ assert( jan01.validYMD );
+ assert( jan01.validHMS );
+ assert( pDate->validJD );
+ jan01.validJD = 0;
+ jan01.M = 1;
+ jan01.D = 1;
+ computeJD(&jan01);
+ return (int)((pDate->iJD-jan01.iJD+45300000)/86400000) + 1;
+}
+
+/*
+** Return the day of the week. 1==Monday, 2=Tues, ..., 7=Sunday.
+*/
+static int dayOfWeek(DateTime *pDate){
+ int w;
+ assert( pDate->validJD );
+ w = ((pDate->iJD+129600000)/86400000) % 7;
+ if( w==0 ) w = 7;
+ return w;
+}
+
+/*
+** Compute the day-of-week (0=Sunday, 1=Monday, ..., 6=Saturday) for
+** the last day of the calendar year Y.
+*/
+static int lastDayOfYear(int Y){
+ return (Y + (Y/4) - (Y/100) + (Y/400))%7;
+}
+
+/*
+** Return the number of ISO weeks in calendar year Y. The answer is
+** either 52 or 53.
+*/
+static int weeksInYear(int Y){
+ if( lastDayOfYear(Y)==4 || lastDayOfYear(Y-1)==3 ){
+ return 53;
+ }else{
+ return 52;
+ }
+}
+
+/*
+** Compute the number days since the start of the ISO-week year for pDate.
+** The ISO-week year starts on the first day of the week (always a Monday)
+** that contains the first Thursday on or after January 1.
+*/
+static int isoWeekNumber(DateTime *pDate){
+ int wn = (10 + dayOfYear(pDate) - dayOfWeek(pDate))/7;
+ if( wn<1 ){
+ wn = weeksInYear(pDate->Y-1);
+ }else if( wn>weeksInYear(pDate->Y) ){
+ wn = 1;
+ }
+ return wn;
+}
+
+/*
** strftime( FORMAT, TIMESTRING, MOD, MOD, ...)
**
** Return a string described by FORMAT. Conversions as follows:
**
-** %d day of month
+** %d day of month 01-31
+** %e day of month 1-31
** %f ** fractional seconds SS.SSS
+** %F ISO date. YYYY-MM-DD
+** %G ISO year corresponding to %V 0000-9999.
+** %g 2-digit ISO year corresponding to %V 00-99
** %H hour 00-24
-** %j day of year 000-366
+** %k hour 0-24 (leading zero converted to space)
+** %I hour 01-12
+** %j day of year 001-366
** %J ** julian day number
+** %l hour 1-12 (leading zero converted to space)
** %m month 01-12
** %M minute 00-59
+** %p "am" or "pm"
+** %P "AM" or "PM"
+** %R time as HH:MM
** %s seconds since 1970-01-01
** %S seconds 00-59
-** %w day of week 0-6 Sunday==0
-** %W week of year 00-53
+** %T time as HH:MM:SS
+** %u day of week 1-7 Monday==1, Sunday==7
+** %w day of week 0-6 Sunday==0, Monday==1
+** %U week of year 00-53 (First Sunday is start of week 01)
+** %V week of year 01-53 (First week containing Thursday is week 01)
+** %W week of year 00-53 (First Monday is start of week 01)
** %Y year 0000-9999
** %% %
*/
@@ -1288,7 +1364,7 @@ static void strftimeFunc(
sqlite3_str_appendf(&sRes, cf=='d' ? "%02d" : "%2d", x.D);
break;
}
- case 'f': {
+ case 'f': { /* Fractional seconds. (Non-standard) */
double s = x.s;
if( s>59.999 ) s = 59.999;
sqlite3_str_appendf(&sRes, "%06.3f", s);
@@ -1298,6 +1374,21 @@ static void strftimeFunc(
sqlite3_str_appendf(&sRes, "%04d-%02d-%02d", x.Y, x.M, x.D);
break;
}
+ case 'G': /* Fall thru */
+ case 'g': {
+ int Y = x.Y;
+ if( x.M==12 && isoWeekNumber(&x)==1 ){
+ Y++;
+ }else if( x.M==1 && isoWeekNumber(&x)>=52 ){
+ Y--;
+ }
+ if( cf=='g' ){
+ sqlite3_str_appendf(&sRes, "%02d", Y%100);
+ }else{
+ sqlite3_str_appendf(&sRes, "%04d", Y);
+ }
+ break;
+ }
case 'H':
case 'k': {
sqlite3_str_appendf(&sRes, cf=='H' ? "%02d" : "%2d", x.h);
@@ -1311,25 +1402,12 @@ static void strftimeFunc(
sqlite3_str_appendf(&sRes, cf=='I' ? "%02d" : "%2d", h);
break;
}
- case 'W': /* Fall thru */
- case 'j': {
- int nDay; /* Number of days since 1st day of year */
- DateTime y = x;
- y.validJD = 0;
- y.M = 1;
- y.D = 1;
- computeJD(&y);
- nDay = (int)((x.iJD-y.iJD+43200000)/86400000);
- if( cf=='W' ){
- int wd; /* 0=Monday, 1=Tuesday, ... 6=Sunday */
- wd = (int)(((x.iJD+43200000)/86400000)%7);
- sqlite3_str_appendf(&sRes,"%02d",(nDay+7-wd)/7);
- }else{
- sqlite3_str_appendf(&sRes,"%03d",nDay+1);
- }
+ case 'j': { /* Day of year. Jan01==1, Jan02==2, and so forth */
+ int nDay = dayOfYear(&x);
+ sqlite3_str_appendf(&sRes,"%03d",nDay);
break;
}
- case 'J': {
+ case 'J': { /* Julian day number. (Non-standard) */
sqlite3_str_appendf(&sRes,"%.16g",x.iJD/86400000.0);
break;
}
@@ -1372,13 +1450,33 @@ static void strftimeFunc(
sqlite3_str_appendf(&sRes,"%02d:%02d:%02d", x.h, x.m, (int)x.s);
break;
}
- case 'u': /* Fall thru */
- case 'w': {
+ case 'u': /* Day of week. 1 to 7. Monday==1, Sunday==7 */
+ case 'w': { /* Day of week. 0 to 6. Sunday==0, Monday==1 */
char c = (char)(((x.iJD+129600000)/86400000) % 7) + '0';
if( c=='0' && cf=='u' ) c = '7';
sqlite3_str_appendchar(&sRes, 1, c);
break;
}
+ case 'U': { /* Week num. 00-53. First Sun of the year is week 01 */
+ int wd; /* 0=Sunday, 1=Monday, 2=Tuesday, ... 7=Saturday */
+ int nDay; /* Day of the year. 0..364 or 0..365 for leapyears */
+ nDay = dayOfYear(&x);
+ wd = (int)(((x.iJD+43200000)/86400000 + 1)%7);
+ sqlite3_str_appendf(&sRes,"%02d",(nDay+6-wd)/7);
+ break;
+ }
+ case 'V': { /* Week num. 01-53. First week with a Thur is week 01 */
+ sqlite3_str_appendf(&sRes,"%02d", isoWeekNumber(&x));
+ break;
+ }
+ case 'W': { /* Week num. 00-53. First Mon of the year is week 01 */
+ int wd; /* 0=Monday, 1=Tuesday, ... 6=Sunday */
+ int nDay; /* Day of the year. 0..364 or 0..365 for leapyears */
+ nDay = dayOfYear(&x);
+ wd = (int)(((x.iJD+43200000)/86400000)%7);
+ sqlite3_str_appendf(&sRes,"%02d",(nDay+6-wd)/7);
+ break;
+ }
case 'Y': {
sqlite3_str_appendf(&sRes,"%04d",x.Y);
break;
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