SQLite

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.102 2009/01/30 17:27:44 drh Exp $
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5

    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9': {
      double rRounder;
      n = getValue(z, &r);
      assert( n>=1 );
      if( z[n]==':' ){
        /* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the
        ** specified number of hours, minutes, seconds, and fractional seconds
        ** to the time.  The ".FFF" may be omitted.  The ":SS.FFF" may be
        ** omitted.

      z += n;
      while( sqlite3Isspace(*z) ) z++;
      n = sqlite3Strlen30(z);
      if( n>10 || n<3 ) break;
      if( z[n-1]=='s' ){ z[n-1] = 0; n--; }
      computeJD(p);
      rc = 0;
      rRounder = r<0 ? -0.5 : +0.5;
      if( n==3 && strcmp(z,"day")==0 ){
        p->iJD += (sqlite3_int64)(r*86400000.0 + rRounder);
      }else if( n==4 && strcmp(z,"hour")==0 ){
        p->iJD += (sqlite3_int64)(r*(86400000.0/24.0) + rRounder);
      }else if( n==6 && strcmp(z,"minute")==0 ){
        p->iJD += (sqlite3_int64)(r*(86400000.0/(24.0*60.0)) + rRounder);
      }else if( n==6 && strcmp(z,"second")==0 ){
        p->iJD += (sqlite3_int64)(r*(86400000.0/(24.0*60.0*60.0)) + rRounder);
      }else if( n==5 && strcmp(z,"month")==0 ){
        int x, y;
        computeYMD_HMS(p);
        p->M += (int)r;
        x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
        p->Y += x;
        p->M -= x*12;
        p->validJD = 0;
        computeJD(p);
        y = (int)r;
        if( y!=r ){
          p->iJD += (sqlite3_int64)((r - y)*30.0*86400000.0 + rRounder);
        }
      }else if( n==4 && strcmp(z,"year")==0 ){
        int y = (int)r;
        computeYMD_HMS(p);
        p->Y += y;
        p->validJD = 0;
        computeJD(p);
        if( y!=r ){
          p->iJD += (sqlite3_int64)((r - y)*365.0*86400000.0 + rRounder);
        }
      }else{
        rc = 1;
      }
      clearYMD_HMS_TZ(p);
      break;
    }
    default: {

# 2003 October 31
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing date and time functions.
#
# $Id: date.test,v 1.32 2009/01/30 17:27:44 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Skip this whole file if date and time functions are omitted
# at compile-time
#

datetest 13.5 {strftime('%Y-%m-%d %H:%M:%f', '2007-01-01 12:59:59.6')} \
  {2007-01-01 12:59:59.600}
datetest 13.6 {strftime('%Y-%m-%d %H:%M:%S', '2007-01-01 23:59:59.6')} \
  {2007-01-01 23:59:59}
datetest 13.7 {strftime('%Y-%m-%d %H:%M:%f', '2007-01-01 23:59:59.6')} \
  {2007-01-01 23:59:59.600}

# Ticket #3618
datetest 13.11 {julianday(2454832.5,'-1 day')} {2454831.5}
datetest 13.12 {julianday(2454832.5,'+1 day')} {2454833.5}
datetest 13.13 {julianday(2454832.5,'-1.5 day')} {2454831.0}
datetest 13.14 {julianday(2454832.5,'+1.5 day')} {2454834.0}
datetest 13.15 {julianday(2454832.5,'-3 hours')} {2454832.375}
datetest 13.16 {julianday(2454832.5,'+3 hours')} {2454832.625}
datetest 13.17 {julianday(2454832.5,'-45 minutes')} {2454832.46875}
datetest 13.18 {julianday(2454832.5,'+45 minutes')} {2454832.53125}
datetest 13.19 {julianday(2454832.5,'-675 seconds')} {2454832.4921875}
datetest 13.20 {julianday(2454832.5,'+675 seconds')} {2454832.5078125}
datetest 13.21 {julianday(2454832.5,'-1.5 months')} {2454786.5}
datetest 13.22 {julianday(2454832.5,'+1.5 months')} {2454878.5}
datetest 13.23 {julianday(2454832.5,'-1.5 years')} {2454284.0}
datetest 13.24 {julianday(2454832.5,'+1.5 years')} {2455380.0}

datetest 13.30 {date('2000-01-01','+1.5 years')} {2001-07-02}
datetest 13.31 {date('2001-01-01','+1.5 years')} {2002-07-02}
datetest 13.32 {date('2002-01-01','+1.5 years')} {2003-07-02}
datetest 13.33 {date('2002-01-01','-1.5 years')} {2000-07-02}
datetest 13.34 {date('2001-01-01','-1.5 years')} {1999-07-02}

# Test for issues reported by BareFeet (list.sql at tandb.com.au)
# on mailing list on 2008-06-12.
#
# Put a floating point number in the database so that we can manipulate
# raw bits using the hexio interface.
#
do_test date-14.1 {