/*
** Return TRUE if the string begins with something that looks roughly
** like an ISO date/time string.  The SQLite date/time functions will
** have the final say-so about whether or not the date/time string is
** well-formed.
*/
static int is_date(const char *z){
int fossil_isdate(const char *z){
  if( !fossil_isdigit(z[0]) ) return 0;
  if( !fossil_isdigit(z[1]) ) return 0;
  if( !fossil_isdigit(z[2]) ) return 0;
  if( !fossil_isdigit(z[3]) ) return 0;
  if( z[4]!='-') return 0;
  if( !fossil_isdigit(z[5]) ) return 0;
  if( !fossil_isdigit(z[6]) ) return 0;

    rid = db_int(0, 
      "SELECT objid FROM event"
      " WHERE mtime<=julianday(%Q,'utc') AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      &zTag[5], zType);
    return rid;
  }
  if( is_date(zTag) ){
  if( fossil_isdate(zTag) ){
    rid = db_int(0, 
      "SELECT objid FROM event"
      " WHERE mtime<=julianday(%Q,'utc') AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      zTag, zType);
    if( rid) return rid;
  }

    db_finalize(&q);
    return rid;
  }

  /* symbolic-name ":" date-time */
  nTag = strlen(zTag);
  for(i=0; i<nTag-10 && zTag[i]!=':'; i++){}
  if( zTag[i]==':' && is_date(&zTag[i+1]) ){
  if( zTag[i]==':' && fossil_isdate(&zTag[i+1]) ){
    char *zDate = mprintf("%s", &zTag[i+1]);
    char *zTagBase = mprintf("%.*s", i, zTag);
    int nDate = strlen(zDate);
    if( sqlite3_strnicmp(&zDate[nDate-3],"utc",3)==0 ){
      zDate[nDate-3] = 'z';
      zDate[nDate-2] = 0;
    }